How does the standard set controller manage state?

Question

I have a VF datatable, where the user needs to update some fields on each record, and there can be thousands (though less than 10k). I learned that I could do that with the StandardSetController, and it worked great! Except I don't know how it manages the state so well. I think the connection is between the getQueryLocator, setting the Pagesize and the pagination. Can someone break it down for me?

 setCon = new ApexPages.StandardSetController(Database.getQueryLocator([
    SELECT 
      Id, Name, Cf1__c, Cf2__c, Cf3__c,Cf4__c, Cf__c
    FROM Account
    WHERE 
    LIMIT 10000
  ])); 

  setCon.setPageSize(PAGE_SIZE);