Question

what is the different between primary and secondary number ​

Answer 1

There is only one primary user. There can be more than one secondary user. The primary user gives secondary users access to particular parts of the system and lets them do specific tasks only. If you're upgrading and have tasks to complete, you'll need to sign in as the primary user

Answer 2

Answer:

Primary sources can be described as those sources that are closest to the origin of the information. They contain raw information and thus, must be interpreted by researchers. Secondary sources are closely related to primary sources and often interpret them.