SRP is for the storage of community content, commonly referred to as user generated content (UGC). User credentials and profiles are not stored in SRP.
Essentially, there is no difference between an AEM Community user and a common AEM user.
Conceptually :
A Community user exists only in the publish environment and commonly is referred to as a 'member'. The JCR path, /home/users/community, has permissions which allow one member to see another member's profile for activities such as 'following'.
The 'common' AEM user exists in the author environment for purposes of authoring, administering, deploying, developing and managing.
- JK