SPContext class in SharePoint 2010

- Represents the context of an HTTP request in Microsoft SharePoint Foundation.

- This class also available in SharePoint Sandboxed solution also.

- Present in the Assembly  Microsoft.SharePoint.dll.

- This class returns current information about list, site and also site collection, also you can retrieve current user name also.

- Here are some example of SPContext class

  string userLoginName=SPContext.Current.Web.CurrentUser.LoginName; //This will return current login name.

  

  SPList currentList = SPContext.Current.List; //Give you the current list associated with the context

  

  SPWeb currentWeb = SPContext.Current.Web; //Returns the current site associated with the context

  

  SPSite currentSite = SPContext.Current.Site; //Returns current site collection associated with the context

  

  SPWebApplication currentWebApplication = SPContext.Current.Site.WebApplication; //Returns current web application associated with the context.

 SPContext.Current.SiteFeatures //Give you the activated site collection features of the SharePoint context.

You can check more on msdn in this URL: http://msdn.microsoft.com/en-us/library/microsoft.sharepoint.spcontext.aspx