Ruby gems are Ruby programs and libraries with a name, version and the platform that can execute them.
List the installed gems on your system
gem list
Detailed list that includes the author, homepage, license, install location and a short description
gem list -d
Install the latest version of the gem
gem install GEM_NAME
Install a specific version of the Gem
gem install GEM_NAME -v GEM_VERSION
Uninstall the gem from your system
gem uninstall GEM_NAME
Uninstall a gem from a specific location
gem uninstall GEM_NAME -i LOCATION_FROM_GEM_LIST_-D
Update the Gem list in your system after Gem uninstallation
gem update --system