What are Ruby Gems?
Gems are the Ruby equivalent of PHP libraries, providing built-in functionality for programming.
Linux Deluxe, Premium, Unlimited, and Ultimate Linux hosting accounts already have a selection of installed Gems whose versions are kept current. To see what Gems are installed on your hosting account, see What Ruby Gems are installed on my hosting account?
To see if you have the correct type of hosting, see What type of hosting account do I have?