SAP User Administration - SU01 

SAP User Administration - SU01
SU01 is used for Creation of users, Lock/ Unlock Users, Specifying User type( Dialog, Communications etc) , Deactivation of passwords etc. You can also use SU01 to assign roles to a User. These roles are generated and maintained using PFCG. Using these roles you can restrict the access to the user of an organization. You can use various objects provided by SAP for defining roles thru PFCG.