A Web interface for git. This instance will be configured to manage Gitolite. See https://github.com/matlink/gitolite_ynh for Gitolite infos.
If you want not to use Gitolite's configuration, you can simply use your own repositories by modifying the configuration file /etc/gitweb.conf to fit your needs. Of course, your git repos might need some more configuration, for example setting the permissions and the owner. Check the gitweb documentation for more infos.