| Family | Generation/Variant | Key Feature | | ---------- | -------------------------- | ---------------------------------------- | | GPT-Series | GPT-4, GPT-4o, GPT-4o-mini | General tasks; "o" means omni/multimodal | | o-Series | | Chain-of-thought reasoning | | | o1 | | | | o1 Pro Mode | | | o-Series | | More advanced reasoning | | | o3-mini | | | | o3-mini-high | "high" has even deeper reasoning | The GPT Series is the first generation of OpenAI models. It **lacks reasoning capabilities** of the O-Series and is **best for general-purpose tasks.** - The "o" in the GPT series stands for "omni," signifying multimodal capabilities (handles not just text but also images, audio, etc.). The O-Series (o1, o3, etc.) are **reasoning models.** They "think" using _chain-of-thought_ reasoning to solve more complex problems in a multi-step series of computation. - The "o" in the O-Series signals that these are reasoning models. (Yes, it is confusing that the GPT Series use the "o" to signify an "omni," or multimodal, model.) The "mini" suffix indicates a smaller, more cost-effective variant of a larger model.