Groups allow you to organize your contacts for easy filtering. This can also be very helpful if you have the Invitations to Bid tool and would like to send an email to a group of contacts.
New Groups can be created from the main People's page as shown below. Select + New, Group, enter Label and click Save:
Once a group is created, you will see the group in Manage Groups page under More buttons:
Manage Groups page allows you to edit or delete groups: