Repository
In plain terms
A storage location for a project's code and its history.
Going deeper
A repository holds all of a project's files plus the complete history of changes tracked by version control. It's the project's source of truth.
Under the hood
In Git, it includes the .git directory with full history; can be local and remote.
Examples
Git repos, GitHub projects, codebases, .git directory, version history.
Think of it like...
Like a project's complete archive, every version preserved.