Translations:Ebuild repository/107/en
From Gentoo Wiki
In practice, any additional ebuild repositories usually aren't just copied to a directory by hand and configured for Portage (meaning added to /etc/portage/repos.conf). Generally, new repositories are made available by third parties, and once configured for Portage, are synchronized by Portage. Synchronization mirrors all the files from a remote location to a locally available filesystem, as configured.