In Chapter 2, Developing Custom Applications, the User table was extended to create the home for the Guest records. It is generally a good idea to keep all your users in the User [sys_user] table, since it lets you use things such as notifications and Connect easily and effectively.
To organize users, put them into groups. Groups and users have a many-to-many relationship. One person can be a member of many groups, and a group can have many members.
Note
Groups are stored in the sys_user_group table. The relationship between groups is stored in the Group Members[sys_user_grmember] table.
Groups are also hierarchical. A group has a reference field pointing to the group table, letting you build up a parent-child structure. A person in a child group is also treated as a member of the parent group in most circumstances.
There are many different uses for groups. To help sort them, there is a list field called Types, though it is not on the form by default. This points to...