Framework is collection of libraries ,class , tool which provide a way for developing a application. it defines structures, methodology, architecture for development of a app. It provide a way of building,testing and run for a app........

http://msdn.microsoft.com/en-us/library/zw4w595w%28v=vs.110%29.aspx

http://www.codeproject.com/Articles/5381/What-Is-A-Framework

its a one type of boundery where more then one language working within the boundery.dotnet is a framework cause it support multiple language like c#,vb.net,j#,etc.

'Framework' provide  domain-specific inheritance hierarchies that are meant for rapid application development in that domain.

frameworks are collections of Tools and technology . It provides Run time environment to languages.