code generation
Code generation is the model's ability to write, complete, explain, and fix programs from a description in plain language or from a half-finished file. Ask for a function that sorts a list or a script that renames your photos, and a capable model produces working code, often with comments and a usage example. It can also read an error message, locate the likely bug, and propose a patch. This has become one of the most genuinely useful things models do, since so much of programming is patterns over a vast but learnable vocabulary.
Code is a special domain because correctness is checkable: you can run it. That tight feedback loop is why coding is central both to training reasoning models and to using them well, since a model can write code, execute it, read the failure, and try again. The honest caveats matter, though. Generated code can be subtly wrong, insecure, or quietly out of date with a library, and it looks just as confident when it is broken. Treat it as a fast, fluent draft from a junior helper, to be read, tested, and understood before you trust it.