The Group Application is a Facebook feature which allows users to create groups. Groups often are made up of people having a similarity. The title is usually enough to show what the group is about. Groups can have an seemingly infinite amount of people.
There are three main group types available in Facebook.
An open group is accessible by any person on Facebook. Anyone, including non-members, can view the group content and the group information. Most groups on Facebook are open groups. They can also join at their own will. The most popular groups on Facebook that are open groups are often topics about people that many have in common, especially daily activities.
World-record groups (groups wanting to set a world record on Facebook) are usually Open Groups; this allows them to maximize their potential.
A closed group has features closed to only members of the group. Members can only be invited by an administrator, or have a request to go in the group. The group information is open to them, but the discussion board and other features are closed to them.
A hidden group is basically hidden from other members. They don't come up on searches. Members must be invited only to be inside. It doesn't appear in a user's list of groups.
This section of a group is at the top and is visible to non-members in an open group and a closed group. This contains the name of the group, the category it belongs to, a basic description of the group, and contact information.
This section contains news about a group that is changed frequently. As the topic says, it states recent news about the group.
This strip displays the members of a group. Up to 8 people are shown at a time. Usually, friends are shown on here along with other people. This does not display all of the members of a group, unless that group has 8 or less members.