Attention Spotlight

That glow is attention. When the model reads a word, it quietly asks "which earlier words does this point back to?" and shines a brighter light on the ones that matter most. That's literally how it figures out what a word like "it" means. And notice the magic trick: flip a single word — "big" to "small" — and the whole spotlight jumps to a different word. Same sentence shape, totally different meaning. This one idea, repeated over and over, is the beating heart of the Transformer behind every chatbot.