IL opcodes documentation designed with dynamically building assemblies in C# in mind. This documentation implies you know the basics of C# and programming fundamentals, but not how a computer operates at the deep level of understanding (e.g. stacks, heap, instructions, opcodes, etc.)
If you don't know what IL is, it stands for Intermediate Language, also referred to as Common Intermediate Language (CIL). CIL is the one that's used in generating IL code for dynamic assemblies in C#.