Link to get all users that ever had access to a SharePoint site

Question

I want to obtain all users that ever had access to a SharePoint site.

Is it correct that I have to use this?

http://sharepointsite/_layouts/15/people.aspx?MembershipGroupId=0

Can I get the XML of that page as well?

What's the difference between the link above and this one:

/_api/web/siteusers

Answer 1

Yes, you could use the url http://sharepointsite/_layouts/15/people.aspx?MembershipGroupId=0, this is user infomation list. In SharePoint, we have the User Information List in SharePoint, which stores information about users. Some examples are Picture, Email, DisplayName, LoginName, and more.

When we grant any user permissions to a user, they are added automatically to the hidden User Information list a new item will be created in the User Information List storing some information about the user.

Below article would help you know more about user infomation list: https://gallery.technet.microsoft.com/office/User-Information-List-in-8b420e8c

This one /_api/web/siteusers is SharePoint rest Service. SharePoint rest Service is for developers mostly. Developers can interact remotely with SharePoint data by using any technology that supports REST web requests. This means that developers can perform Create, Read, Update, and Delete (CRUD) operations from their SharePoint Add-ins, solutions, and client applications, using REST web technologies and standard Open Data Protocol (OData) syntax.

Please read this article for more about sharepoint rest service:

https://docs.microsoft.com/en-us/sharepoint/dev/sp-add-ins/get-to-know-the-sharepoint-rest-service?tabs=csom