A skill is a folder with instructions and sometimes scripts or templates. The agent reads it when the task comes up, so that it does not have to be explained over and over again. Claude Code and several other agents use skills.
Skills make the work repeatable. Instead of every developer writing their own instructions, the team shares the same skills and gets the same result. We use skills for everything from code review to writing quotes.
Skills go together with commands and hooks. The command starts a workflow, the skill describes how it is done and the hook stops what must never happen.
