title: What does the GUID in C# Programs in the AssemblyInfo.cs?
body: <p>I'm wondering for what the GUID in the AssemblyInfo.cs in C# Programs is:
  <code>[assembly: Guid("a4df9f47-b2d9-49a9-b237-09220857c051")]</code></p>
  
  <p>The commentary says it's for COM objects, but why do they need a GUID?
  Is the GUID accessibly externally?</p>
  
  <p>So if it's only for COMs, do you need a GUID when you set <code>[assembly: ComVisible(false)]</code>?</p>