group is a name service database used to store group information on Unix-like operating systems. The sources for the group database (and hence the sources for groups on a system) are configured, like other name service databases, in nsswitch.conf.
Contents
Seeing available groups on a Unix system
The contents of the group database (and available groups) can be seen with a variety of tools:
Command line
The getent command can be used to fetch group information.
Fetching a list of all available groups
getent groupFetching a specific group
For a specific group called 'users':
getent group usersPython
References
Group (database) Wikipedia(Text) CC BY-SA