A pop up window opens on screen. User needs to fill the record first name, last name, user name and email address of new user and save the records.
After save newly created user display in active user list.
How to assign new user to existing site follow the following steps to do this:
1- Go to site collection, select existing site which ever assign to new user.
2- Go to site collection select Manage administrator under owner tab.
Click on the manage administrators, a dialog box opens
Search the existing user which you want to assign this site. A new dialog box open as shown below.
Click the Ok button. Now this user is authenticated and authorized to access this site.