Create user and grant privileges

create user dba92 identified by dba92;
 revoke create session from dba92;
grant alter user to dba92; -- this user can alter any user;

 drop user dba92 cascade;

--Role is a bundle of related privileges;
create role rolename;
grant rolename to user;

alter user dba92
identified by employ;

--Check privileges
select role, privilege from role_sys_privs;