What is the difference between a DLL and an EXE?

In .NET, an assembly may become a DLL or an EXE. Yet, there is a major underlying difference between the two.

An EXE is an executable file, that may run on its own. Its independant. Where as a DLL is a Dynamic Link Library, that binds to an exe, or another DLL at runtime.

A DLL has an exposed interface, through which members of the assembly may be accessed by those objects that require it.

A DLL runs in tandem with the application space in memory, as the application references it. Whereas an EXE is independant, and runs as an independant process.