Repository

A Repository is a database that contains lists of items. Important examples are:

LQ Wiki is a collaboratively-edited repository for all things regarding Linux
CVS is a centralized repository for source code
SourceForge: the largest repository of Open Source code and applications
Fedora Tracker: a repository of program management repositories and RPM packages related to Fedora. Useful for Apt, Yum, Synaptic, Up2date.