How Self-Attention Works — QKV, Softmax, and Matrix Computation (opens in new tab)

Self-Attention is not just “looking at important words.” It is a matrix operation. And that is exactly why Transformers scale. Core Idea Self-Attention lets each token compare itself with every other token in the same sequence. Each token asks: Which other tokens are useful for updating my representation? This matters because meaning is contextual. A token should not stay as a static embedding. It should become a representation shaped by the sentence around it. The Key Structure Self-Attentio...