Web applications: A Web application is an IIS Web site that is created and used by SharePoint Products and Technologies. Each Web application is represented by a different Web site in IIS. You assign each Web application a unique domain name, which helps to prevent cross-site scripting attacks.
Generally speaking, use dedicated Web applications to:
· Separate anonymous content from authenticated content. In the model, the company Internet site is hosted in a dedicated Web application and application pool.
· Isolate users. In the model, Partner Web is hosted in a dedicated Web application and application pool to ensure that partners do not have access to the intranet content.
· Enforce permissions. A dedicated Web application provides the opportunity to enforce permissions by policies by using the Policy for Web Application page in Central Administration. For example, you can create a policy on the company Internet site to explicitly deny write access to one or more groups of users. Policies for a Web application are enforced regardless of permissions configured on individual sites or documents within the Web application.
· Optimize performance. Applications achieve better performance if they are placed in Web applications with other applications of similar data characteristics. For example, the data characteristics of My Sites include a large number of sites that are small in size. In contrast, team sites typically encompass a smaller number of very large sites. By placing these two different types of sites in separate Web applications, the resulting databases are composed of data with similar characteristics, which optimizes database performance. In the model, My Sites and team sites do not have unique data isolation requirements — they share the same application pool. Nonetheless, My Sites and team sites are placed in separate Web applications to optimize performance.
· Optimize manageability. Because creating separate Web applications results in separate sites and databases, you can implement different site limits (recycle bin, expiration, and size) and negotiate different service-level agreements. For example, you might allow more time to restore My Site content if this is not the most critical type of content within your organization. This allows you to restore more critical content before restoring My Site content. In the model, My Sites are placed in a separate Web application to enable administrators to more aggressively manage growth compared to other applications.