Number Range for Personnel Numbers

You have two options:

Internal number assignment which the SAP System assigns the personnel numbers.

External number assignment which the user assigns the personnel numbers.

To set the Personnel Numbers range :-

IMG - Personnel Management -> Personnel Administration -> Basic Settings

-> PA04 - Maintain number range intervals for personnel numbers

-> PE03 - Determine defaults for number ranges

For e.g.
01 - External
02 - Internal