Information from Employee settings is used in the system. These settngs are main and it needs to be configured before start working with the system.
Add employee with simple form mean that all unnessesary information will be skipped during employee creation.
You can enable disable sections or fields based on your needs. For example if you are not going to use Emergency Contact you can hide whole section.
You can disable it but it is not recommended. Based on this information all system logic and reports are built.