Differences Between Categories And Repositories
From RockWiki
Categories and repositories are two independent ways to group packages.
Repositories
Top-level subdirectories of package/ in the ROCK Linux sources are called repositories. Each package belongs to the repository that contains its directory.
Repositories are organizational units, e.g. there is one for packages from the KDE project and one for Java packages. Other methods of organisation are to group by maintainer (for example the clifford/ and avm/ repositories) or by type of application (the x11/ repository).
The public/ repository is a special case here. Packages go to this repository when its maintainer ceases work on it for one reason or another. The package becomes maintained by the ROCK Project which means that someone can have the package moved to his personal repository and became the main maintainer. It does not mean that maintenance is stopped entirely, but updates may come less frequently. So if you find a package in the public/ repository that you think should be updated more frequently you can pick up maintenance.
Having the same package name in different repositories is not allowed. To easily find out which package is in which repository, just do
# cd /usr/src/rock-src/package/*/<package>
Categories
Categories group packages by their functionality, e.g. the Linux kernel belongs to the base/kernel category, and gcc belongs to base/development. Packages can belong to more than one category.
The categories is what will be visible to the user when he is installing a new system or querying the package database (see also List of categories).
