How ChatGPT Actually Works

10 min

What you will learn

Explain the GPT architecture including transformers, attention, and token prediction
Describe the three-stage training pipeline: pretraining, SFT, and RLHF
Compare GPT-4o, o1, and GPT-4o mini by capability, speed, and cost
Define temperature, tokens, and hallucination and explain why each matters

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How ChatGPT Actually Works

Understanding how ChatGPT works under the hood transforms you from a passive user into a strategic one. When you know why the model behaves the way it does, you can craft better prompts, interpret responses more accurately, and avoid common frustrations. This lesson explains the technology behind ChatGPT in practical terms — no machine learning degree required.

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Knowledge check

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What does the 'G' in GPT stand for?

Key takeaway

ChatGPT is a next-token prediction engine refined with human feedback — understanding this helps you write prompts that play to its strengths and avoid its weaknesses.