Before we get into defining the GIS-tier and the Web-tier, we should first discuss the user and role stores. To provide proper data and network security, ArcGIS for Server must identify requests that are made to the GIS services. This is done by cross-referencing a user with the roles granted to that user. By doing so, Server can authenticate requests and allow or deny access to the subject GIS service according to the assigned roles. To achieve that, Server requires two tables, the Users and Roles tables. Configuring these tables or stores can be done either by manually populating the users and roles stores, where the stores will be maintained by Server, or linking it to the Windows domain. We will discuss how to do this in the coming pages.