How to determine which assembly a specific class belongs to? <p>Often i have a problem that I need to determine which assebmly to include into my project in order to use specific class. For instance I want to you TypeInfo class. MSDN does not say it belongs to. Actually I am not even been able to find TypeInfo class using MSDN document explorer search. All the results relate to some other stuff. For instance first result is about System.Runtime.Remoting. </p> <p>Also MSDN says - assembly mscorlib. In the components page of Add Reference dialog box i can see mscorlib but also fully qualified names like System.RunTime.Serialization</p> <p>What is the difference? </p>