What is the basis for Employee Group & Employee Sub Group?

Question

Dear Consultants,
1) How to finalize the Employee Group and Employee Sub Group?
2) What points should be taken into consideration before finalizing Employee Group and Employee Sub Group?
3) In which places we can use Employee Group?
4) In which place we can use Employee Sub Group?
5) What items/sub-modules in SAP-HR largely depends on Employee Group and Employee Sub Group?
6) What kind of problem could arise with wrong Employee Group and Employee Sub Group?
Let's have the answer for this question, which could help all the members.

Answer 1

An organizational unit for which personnel provisions can be specified.
Example
Employee groups:
Active employees
Employees who have left the company
Company pensioners
Employee subgroups within the "active employee" group:
Industrial workers
Commercial employees
Technical employees
Employee subgroup
An organizational unit within an employee group for which personnel provisions have been defined.
ESG groupings
Grouping of employee subroups in Payroll for the following purposes:
Work schedule
Personnel calculation rules
Primary wage types
Collective agreement rules
Time quota types
Account determination