By default, accounts are added into one of the following groups: standard or editor. In addition to this, you can create your own groups so that the management of accounts becomes even easier.
You can create a group by clicking on create group, typing the preferred name of the group, and then clicking save. After this, you need to select the accounts you want to add and click on assign to groups. If you want to remove a user from a group, you simply untick the checkbox.