Difference between Web Application, Site Collection and Site

Web Application

On top of the hierarchy is the web application. In technical terms, this is a web site in IIS (with an associated application pool). A default web site listens for incoming HTTP requests on port number 80. But we can create additional web sites, having different port numbers or IP addresses. We can configure each IIS web application independently. We can have one web application configured in anonymous access one in integrated authentication etc.

The SPWebApplication objects represent a SharePoint Web Application, which essentially is an IIS virtual server. Using this class we can do some high level operations. Please find some of the actions you can perform.

  • Create a web application

  • Collect all the features in a particular web application

  • Delete a web application

  • Some administrative task for the web application.

Site Collection

The Site Collection is the root site of the web site. Below the Site Collection, there can be one or more Sites. A Site Collection is a collection of SharePoint sites;  i.e. a SharePoint site collection is a logical grouping of multiple SharePoint sites.

There are many reasons to go with separate site collection in SharePoint. Some of the features are listed below.

  • Dedicated Recycle bins
  • Dedicated usage Reports
  • Site collection administrator option for each site collection
  • We can set search scopes, keywords, etc
  • We can deploy features specific to a site collection
  • Each site collection has Galleries for web parts, master pages, content Type etc
  • Administrators can set Site quota templates for Site collection (Max Size of the Site collection)
  • Database maintenance options
  • Backup / Restore abilities
  • Content Deployments options

A user assigned as a site collection administrator has full rights on the existing site as well as any other sites that would be created in the same site collection. We can define Security groups, users and their authorization rights independently for each Site collection. Another main advantage is easy to take backup/Restore site collection. As SharePoint is all about data and data should be properly authenticated / authorized to proper users. By defining the structure in site and site collection we can now define roles and responsibilities according to data.


Site is a collection of web pages which is used to store information in an organized way. Site stores list of documents, discussion, events, task and many other types of information. Site provides controlled access to share information among user;  i.e. only authorized users are allowed to access shared information. You can have multiple sites under each site collection; each site can have multiple sub sites also.