Variable:Wizard General information

Hi,

I am creating variables for authorization purpose:During variables creation in Wizard General information we will get variable --->1.userentry/defaul value.

2Replacement path.

3.customer exit.

4.SAP Exit.

5.Authorization.

Can any one explain the significant of these ponts.

The fifth point is it related to the authorization?

Cheers,

Pradeep.