How Transformers Work — From Self-Attention to Modern LLM Architecture (opens in new tab)

Transformers changed AI because they stopped reading sequences one token at a time. Instead of moving step by step like an RNN, a Transformer compares tokens directly. That one design shift made modern LLMs possible. Core Idea A Transformer is a neural network architecture built around attention. It looks at a sequence of tokens and learns how those tokens relate to each other. This matters because language is contextual. A word is not understood alone. It is understood through its relationsh...