What Is an Assembly?

In the simplest case, when you write a program in Windows, a compiler converts your source code into an executable file (.exe). For bigger projects that group functions used repeatedly by various parts of the program, the compiler produces Dynamic Link Libraries (DLLs), which can be called from the outside, thus avoiding redundancies and saving space. You can picture a DLL as a set of classes and methods that cannot run on their own, but that can make those classes and methods available to any number of .exe files.

Under .NET, all this works pretty much the same way, but there is one fundamental difference. In their compiled intermediary code state (more about that later in the section about Just-in-Time compilers), the .exe ...

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