In simple terms, AI models are like digital brains trained on massive amounts of data to understand language, images, code, and human instructions.
Different companies build different models because each one is trained differently, designed for different goals, and better at certain tasks, such as writing, coding, reasoning, image, or video generation.
What is an AI Model in a simple analogy
An AI model is like a student that has read billions of books, websites, articles, and conversations from the Internet.
Instead of memorizing exact answers, it learns patterns in language, images, code, and reasoning so it can predict what comes next, similar to how your phone predicts the next word when typing, but on a much more advanced level.
In general, larger models with better training data and more advanced training methods tend to give smarter, more accurate, and more human-like responses.
Limitations of AI Models
Despite their impressive capabilities, AI models still have important limitations. They can sometimes “hallucinate” by confidently generating incorrect or completely made-up information, and their answers are not always factually accurate.
AI models may also reflect biases from their training data, struggle with complex reasoning in certain situations, and some models may rely on outdated knowledge if they are not connected to real-time information sources.
Large Language Model (LLM)
A Large Language Model (LLM) is a type of AI designed to understand and generate human language.
“Large” means it is trained on massive amounts of data from books, websites, articles, and conversations, “Language” means it works mainly with words and text, and “Model” refers to the AI system itself.
Popular LLMs like ChatGPT, Claude, and Gemini can answer questions, write content, summarize information, translate languages, and even generate code.
Main Types of AI Models:
Generally, AI models are categorized into several major types, including flagship large language models (LLMs), open-source models, image generation models, video generation models, coding models, and audio or speech models.
Let’s get started with flagship LLMs
Part I: Closed-source Flagship LLMs
1. GPT — OpenAI’s Flagship LLM Series
ChatGPT is powered by the GPT model family, which evolved from GPT-1, GPT-3, GPT-3.5 (arguably the most iconic version that triggered the global AI boom after ChatGPT launched in November 2022), GPT-4 (released in March 2023), GPT-4o, GPT-5, and newer variants like GPT-5.2.
ChatGPT offers several pricing tiers, including Free, Go, Plus, and Pro plans.
As an all-round AI assistant, ChatGPT performs well in writing, coding, web search, question answering, image generation, PDF analysis, and voice interactions, although some users feel its responses can occasionally be too long or overly cautious.
Quick note: ChatGPT itself is not the AI model — GPT is the model. ChatGPT is the application or interface (similar to Microsoft Copilot, Gemini, or Claude), while GPT is the “brain” operating behind the scenes.
2. Gemini — Best Integration with the Google Ecosystem
Gemini is Google’s flagship AI assistant and one of the strongest competitors to GPT models. Gemini is deeply integrated into the Google ecosystem, including Search, Gmail, Docs, Sheets, YouTube, and Android devices, making it especially convenient for everyday productivity and web-based tasks.
Gemini offers several plans, including Gemini Free, AI Plus, AI Pro, and AI Ultra.
Its strengths include fast responses, strong web search capabilities, video understanding, image generation, and seamless integration with Google services.
Features like AI Mode and AI Overviews help users quickly summarize search results, while newer multimodal capabilities allow Gemini to understand text, images, videos, and documents together.
3. Claude — Built for Reasoning, Coding, and Work Tasks
Claude is an AI assistant developed by Anthropic and is widely known for its strong reasoning, coding, and writing abilities. Many users prefer Claude for professional work because it handles long documents well, produces natural writing, and performs strongly in coding, research, spreadsheets, reports, and other office-related tasks.
Claude currently offers Free, Pro, and Max plans (starting from around $100/month), with advanced models such as Claude Opus 4.6 powering higher-tier experiences.
Unlike some competitors, Claude focuses more on productivity and reasoning rather than image generation. Its strengths include coding assistance, document analysis, integrations, tools, workflow automation, and “skills” that help users complete complex work tasks more efficiently.
4. Perplexity Sonar — AI Search and Research Assistant
Perplexity is an AI-powered search and research assistant designed to give fast, accurate answers with real-time web sources and citations. Unlike traditional chatbots that mainly rely on pre-trained knowledge, Perplexity focuses heavily on live web search, making it especially useful for research, fact-checking, news, and discovering up-to-date information.
Perplexity uses its Sonar model family alongside other AI models to improve search accuracy and reasoning. Its strengths include fast web browsing, source citations, research summaries, and answering complex questions with references — making it popular among students, researchers, marketers, and professionals who need reliable information quickly.
Perplexity offers both Free and Pro plans, with Pro users gaining access to more advanced AI models, deeper research features, and higher usage limits.
5. Grok — AI Integrated with the X Platform
Grok is an AI assistant developed by xAI and is closely integrated with the X (formerly Twitter) platform. Grok is designed to provide real-time information, social media insights, and conversational AI experiences, making it useful for trending topics, live discussions, and internet culture.
Its strengths include real-time X search, image generation, voice interaction, and fast access to trending content directly from the X ecosystem. Compared to some other AI assistants, Grok is known for having a more casual and humorous personality style.
Grok offers both free access and premium tiers such as SuperGrok and SuperGrok Heavy, which provide higher usage limits and access to more advanced AI features.
DeepSeek — Rising Open-Source AI Challenger
DeepSeek is a Chinese AI model family developed by DeepSeek, a company backed by the quantitative hedge fund High-Flyer. DeepSeek quickly gained global attention for delivering strong reasoning, mathematics, and coding performance while offering many of its models as open-weight models that developers can freely access and run themselves.
DeepSeek is especially popular among developers and technical users because of its fast performance, lower operating costs, and strong coding capabilities. Many people see it as one of the biggest open competitors to GPT and Claude in the AI industry.
Part II: Open-Source AI Models
Understanding Open-Source AI Models
Open-source (or more accurately, open-weight) AI models are AI systems that developers can freely download, run, modify, and customize on their own computers or servers.
Unlike flagship closed-source AI models such as ChatGPT, Claude, or Gemini — where users only access the AI through a company’s app or website — open-source models give developers much more freedom and control.
In simple analogy:
- Closed-source AI is like renting a hotel room.
- Open-source AI is like owning the house yourself.
Advantages of Open-Source AI Models
With open-source models, you can run the AI locally on your own PC, similar to installing software like a video game or Photoshop instead of using a cloud-based app. This gives users more privacy, customization, and long-term cost savings because your data stays on your machine, and many models are free to use.
Drawbacks of Open-Source AI Models
However, open-source AI also comes with drawbacks. Setting up and running these models can be more technical, often requiring decent hardware, GPU power, coding knowledge, and tools such as Docker and Python. For beginners and non-technical users, closed-source AI platforms are usually much easier to use.
Popular Open-Source AI Models:
1. Meta’s Llama
Llama is one of the world’s most popular open-weight AI model families developed by Meta. It helped accelerate the open-source AI movement by allowing developers and companies to build their own AI tools locally.
2. Qwen (通义千问)
Qwen is an open-weight AI model family developed by Alibaba. Qwen is known for strong multilingual proficiency, coding skills, and a good understanding of Chinese.
3. DeepSeek
DeepSeek became famous for delivering high-level reasoning and coding performance at relatively low cost. Many developers use it as an open alternative to GPT-style models.
4. MiniMax
MiniMax develops AI models focused on conversational AI, entertainment, and multimodal experiences. It is especially active in China’s rapidly growing AI ecosystem.
5. OpenAI’s GPT-OSS (Open-Source Style)
Although OpenAI is mostly known for closed-source GPT models, the company has explored more open-style releases and ecosystem support over time. However, GPT itself is still primarily a proprietary commercial model family.
6. NVIDIA Nemotron
Nemotron is developed by NVIDIA and focuses heavily on enterprise AI, reasoning, and AI infrastructure optimization. It is commonly associated with high-performance AI computing.
7. Google Gemma
Gemma is Google’s lightweight open-weight AI model family designed for developers and researchers. It is smaller and more accessible compared to Gemini, making it easier to run locally.
8. Kimi K2.5
Kimi is developed by Moonshot AI and is known for long-context understanding and strong Chinese-language performance. It has gained popularity among students and productivity-focused users.
9. GLM-5 (Z.ai)
GLM (General Language Model) is developed by Zhipu AI and focuses on multilingual AI capabilities, reasoning, and enterprise applications. It is part of China’s growing ecosystem of competitive AI models.
10. Mistral AI
Mistral AI is one of Europe’s leading open-weight AI companies. Its models are known for being efficient, lightweight, and highly competitive despite using fewer computing resources than some larger rivals.
Ollama: open-source tool to run LLMs
Ollama is not actually an AI model itself, but an open-source tool designed to let users easily run large language models (LLMs) locally on their own computers. It simplifies the setup process for beginners, making open-source AI models easier to install and use.
Part III: Image-Generation models
Understanding Image Generation Models
Image generation models are AI systems that create images from text instructions, commonly known as “text-to-image” generation.
Users simply type a prompt such as “a futuristic city at sunset in cyberpunk style,” and the AI analyzes the words, understands the patterns it learned from millions of images during training, and generates a completely new image based on that description.
Popular image generation models like DALL·E, Midjourney, and Stable Diffusion are widely used for art, design, marketing, social media, and creative projects.
Popular Image Generation AI Models:
1. Midjourney
Midjourney is one of the most popular AI image generators known for producing highly artistic, cinematic, and visually stunning images. It is especially favored by designers, artists, and creators for concept art and social media visuals.
2. OpenAI’s DALL·E
DALL·E is OpenAI’s image generation model integrated into ChatGPT. It allows users to generate and edit images using natural language prompts, although OpenAI now focuses more on ChatGPT’s built-in image generation experience rather than heavily branding the standalone “DALL·E” name.
Note: “ChatGPT Image 2.0” is not the official replacement name for DALL·E. OpenAI now markets it more as ChatGPT image generation powered by its multimodal GPT models.
3. Stable Diffusion
Stable Diffusion is one of the most famous open-source image generation models. It allows developers and creators to run AI image generation locally on their own computers with high customization and flexibility.
4. Flux
FLUX.1 is a powerful open-weight AI image model developed by Black Forest Labs. It became popular for producing high-quality, realistic images and is considered one of the strongest open alternatives to Midjourney-style generation.
5. Ideogram
Ideogram is an AI image generator particularly known for its ability to create readable text inside images, making it useful for posters, logos, ads, and social media graphics.
6. Grok Imagine
Grok includes image generation capabilities often associated with “Imagine”-style creative tools inside the Grok ecosystem. It focuses on fast image creation integrated with the X platform and conversational AI experiences.
Quick note: When ChatGPT generates an image, the underlying image model is usually different from the text model — traditionally, this was DALL·E or newer multimodal GPT image systems.
Similarly, when Grok generates images, it uses a separate image generation system often associated with Grok Imagine. In many AI platforms, the text model and image model are connected but are technically different systems.
7. Gemini Image aka "Nano Banana"
“Nano Banana” was originally a codename and community nickname for Google’s image generation model within the Gemini ecosystem. Over time, it became associated with Google’s Gemini Image models, including Gemini 2.5 Flash Image and Gemini 3 Pro Image.
These models are designed for AI image generation and editing, and are known for realistic image outputs, strong text rendering inside images, high-quality prompt following, and advanced image editing capabilities.
How to pick the right AI image generation tool?
In a nutshell, different AI image generation tools excel at different things.
For highly artistic and visually stunning images, many users prefer Midjourney.
For ease of use and convenience, many people choose DALL·E because it is built directly into ChatGPT.
For prompt accuracy and realistic outputs, some users prefer FLUX.1;
while designers and advanced users often choose Stable Diffusion for its higher level of customization and control.
Part IV: Video-Generation models
Understanding Video Generation Models
Video generation models are AI systems that create videos from text prompts, images, or existing video clips.
Similar to image generation AI, users can type instructions such as “a drone shot flying over a futuristic city at night,” and the AI generates moving scenes by predicting how objects, lighting, motion, and camera angles should appear frame by frame.
These models are becoming increasingly popular in filmmaking, animation, advertising, gaming, and social media content creation.
Popular Video Generation Models:
1. OpenAI Sora
Sora is OpenAI’s advanced text-to-video generation model capable of creating highly realistic and cinematic AI videos from simple prompts. It became famous for producing smooth motion, realistic environments, and movie-like camera movements.
2. Google Veo
Veo is Google’s high-end AI video generation model focused on cinematic quality, realistic motion, and advanced prompt understanding. Veo is tightly connected to Google’s Gemini ecosystem and multimodal AI strategy.
3. Runway Gen-4
Runway Gen-4 is a popular AI video model widely used by creators, filmmakers, and marketers for AI filmmaking and visual effects. Runway is known for strong editing tools, image-to-video generation, and creator-friendly workflows.
4. Kling
Kling is a Chinese AI video generation model developed by Kuaishou that gained attention for producing highly realistic physics, facial expressions, and cinematic motion. Many users consider it one of the strongest competitors to Sora.
5. Seedance ??
“Seedance 2.0” is not yet as globally recognized as models like Sora, Veo, or Kling, but it is associated with newer AI video generation developments from the Chinese AI ecosystem. It focuses on realistic motion generation, animation quality, and multimodal video creation features.
Part V: Audio Models
Understanding Audio Models (Voice & Music AI)
Audio models are AI systems designed to generate, understand, or transform sound, including voices, music, speech, and sound effects.
Similar to how image models generate pictures from text prompts, audio AI models can convert text into realistic speech (Text-to-Speech or TTS), clone voices, create songs, generate background music, or even produce sound effects.
These models work by learning patterns from massive amounts of audio recordings, allowing them to predict tone, rhythm, pronunciation, melody, and emotion in sound generation.
Popular Audio AI Models
1. ElevenLabs
ElevenLabs is one of the most popular AI voice platforms, known for realistic voice generation and voice cloning technology. It supports multilingual speech generation and is widely used for audiobooks, YouTube narration, gaming, and AI assistants.
2. OpenAI Voice Mode
ChatGPT Voice Mode allows users to have natural, real-time voice conversations with AI. It combines speech recognition, reasoning, and AI-generated speech to create a more human-like conversational experience.
3. Suno
Suno is an AI music generation platform that can create full songs — including vocals, lyrics, instruments, and melodies — from simple text prompts. It became popular for making music creation accessible to non-musicians.
4. Udio
Udio is another advanced AI music generation platform focused on producing high-quality songs and realistic vocals from text prompts. Many users praise it for its musical quality and creative flexibility.
Part VI: Coding Agents & Coding AI Models
Coding Agents & Coding AI Models
Coding agents are AI systems designed to help developers write, understand, debug, and manage code more efficiently.
Unlike normal chatbots, coding agents can interact with files, terminals, development environments, and even entire software projects.
They work by analyzing programming languages and predicting code patterns based on massive amounts of training data from open-source repositories, documentation, and developer workflows.
These tools are commonly used for:
writing code,
fixing bugs,
explaining code,
generating websites/ apps,
automating repetitive tasks,
and accelerating software development.
Further Reading: Vibe Coding
Popular Coding Agents & Coding AI Tools
1. Claude Code
Claude is widely considered one of the strongest AI tools for coding and software reasoning. Many developers use Claude for large codebases, debugging, refactoring, and technical writing because of its strong reasoning and long context window.
2. Cursor
Cursor is an AI-powered code editor built specifically for developers. It integrates AI directly into the coding workflow, allowing users to generate, edit, explain, and debug code inside the editor itself.
3. OpenAI Codex
Codex is OpenAI’s coding-focused AI model that helped power tools like GitHub Copilot. It specializes in understanding programming languages and converting natural language instructions into code.
4. Devin AI
Devin is an AI software engineering agent developed by Cognition Labs. Unlike simple coding assistants, Devin is designed to handle more autonomous development tasks such as planning, coding, debugging, and executing workflows.
5. Factory.ai
Factory focuses on AI-assisted software development and developer productivity workflows. It aims to help engineering teams automate coding and development operations more efficiently.
6. Google AI Studio
Google AI Studio is Google’s platform for developers to experiment with Gemini models, prompts, APIs, and multimodal AI applications. It is commonly used for AI prototyping, coding experiments, and AI app development.
Part VII: FAQs
Frequently Asked Questions on AI Models and LLMs
What Is Multimodal AI?
Multimodal AI refers to AI systems that can understand and work with multiple types of content at the same time, including text, images, audio, video, and documents.
Older AI models mainly understood text only, while modern multimodal AI models can analyze different forms of information together for more human-like interactions.
For example, you can upload a photo of homework and the AI can explain the answer, upload a PDF for summarization, ask questions about an image, or even have a voice conversation with the AI.
Models like ChatGPT and Gemini are examples of multimodal AI systems.
GPT vs ChatGPT, What is the difference?
GPT: A family of AI models (LLMs and multimodal models) that gives AI applications the ability to generate text, create and analyze images, interpret data, reason through problems, and more.
ChatGPT: A chatbot application powered by GPT models. It is optimized for dialogue and conversation, includes safety and content filters, and provides users with an interface to interact with GPT.
Claude Opus and Claude Sonnet, What is the difference?
Claude Opus and Sonnet are two different tiers of Claude models.
In simple terms, Opus is the more powerful “premium brain,” while Sonnet is the faster and more cost-efficient everyday model.
Opus models are generally better for deep reasoning, complex coding, research, and long workflows, while Sonnet models focus more on speed, lower cost, and balanced performance.
For example, Claude Opus 4.7 is designed for harder software engineering and advanced reasoning tasks, with stronger coding and vision performance than earlier versions.
Meanwhile, Claude Sonnet 4.6 is optimized for faster responses, real-time workflows, and enterprise productivity at a lower cost.
What is world models?
World models are AI systems designed to understand and simulate how the real world behaves, including physics, environments, movement, and cause-and-effect relationships. Instead of only predicting text or images, these models try to predict “what happens next” in a virtual or real-world environment — similar to how humans mentally imagine outcomes before taking action.
Examples include Google Genie for interactive virtual environments, World Labs Marble for spatial intelligence, Tesla Full Self-Driving for autonomous driving, and NVIDIA Cosmos for robotics and physical AI simulation.
What is Frontier AI?
Frontier AI refers to the most advanced AI systems at the cutting edge of current technology, usually developed by leading companies such as OpenAI, Google, Anthropic, and xAI. These models push the limits of reasoning, coding, multimodal understanding, robotics, and autonomous AI capabilities.
What is an AI Token?
In AI, a token is a small unit of text that AI models read and process. A token can be a word, part of a word, punctuation, or even a symbol. For example, the sentence “I love AI” may be split into several tokens before the AI understands it.
The Role of Tokens in AI:
Tokens are the “building blocks” AI models use to process language. AI models read prompts token by token, predict the next token, and generate responses the same way. Token limits also determine how much information an AI model can remember in a conversation or document.
What is MCP?
MCP stands for Model Context Protocol, an emerging standard that helps AI models connect with external tools, apps, databases, and software systems in a more structured way.
In simple terms, MCP acts like a “universal connector” that allows AI assistants to interact with other digital tools more efficiently.
What is RAG?
RAG stands for Retrieval-Augmented Generation, a technique that allows AI models to retrieve external information from databases, documents, or the internet before generating an answer. This helps AI provide more accurate, updated, and context-aware responses instead of relying only on pre-trained knowledge.
Gemma vs Gemini
Gemini: Gemini is Google’s flagship cloud-based AI model family that primarily runs on Google’s servers. Users typically access Gemini through web apps, APIs, Android devices, and Google services such as Search, Gmail, and Docs.
Gemma: Gemma is Google’s open-weight AI model family designed for developers and local deployment. Unlike Gemini, Gemma models can run on personal hardware such as laptops, PCs, phones, and even devices like Raspberry Pi, giving users more privacy, control, and lower operating costs.
What Are Autonomous AI Agents?
Autonomous AI agents are AI systems that can perform tasks with minimal human input by planning, reasoning, using tools, and taking actions automatically.
Unlike normal chatbots that only answer questions, AI agents such as Manus, Claude, with tool use, Cowork, and OpenClaw can handle workflows like research, coding, browsing websites, and task automation more independently.
What Is an AI Agent?
An AI agent is an AI system designed to complete goals and tasks instead of only generating responses. It can interact with tools, APIs, files, browsers, or software systems to perform actions such as sending emails, analyzing documents, writing code, or automating workflows.
Agent Skill:
An agent skill is a specific capability or tool an AI agent can use to complete tasks more effectively. Examples include web browsing, file analysis, coding, calendar management, database access, image generation, or connecting with external apps like Slack or Google Drive.
What is an Agentic Workflow?
An agentic workflow is an automated process where AI agents and software tools work together to complete tasks step by step with minimal manual effort.
Platforms such as n8n, Make, and Zapier allow users to build workflows that connect AI models, apps, APIs, and business tools to automate repetitive work and decision-making processes.
What is a Context Window?
A context window refers to how much information an AI model can remember and process at one time during a conversation. A larger context window allows the AI to handle longer chats, bigger documents, more code, or multiple files without forgetting earlier information.
How should Microsoft Copilot, Meta AI, Baidu ERNIE Bot, and Doubao be categorized?
These mostly belong to the Consumer AI Platforms category rather than pure model categories. Many people confuse the AI app/assistant with the underlying AI model.
Tools like Copilot, Meta AI, ERNIE Bot, and Doubao are AI assistants/ platforms powered by one or multiple AI models behind the scenes.
ChatGPT, Copilot, Meta AI, and Doubao are like apps or “AI products,” while GPT, Llama, ERNIE, and Doubao models are the actual AI brains behind them.
| AI Assistant / Platform | Company | Underlying Model |
|---|---|---|
| Microsoft Copilot | Microsoft | Mainly GPT models from OpenAI |
| Meta AI | Meta | Llama models |
| ERNIE Bot | Baidu | ERNIE models |
| Doubao (Dola AI) | ByteDance | Doubao / Seed model family |