So I'm new to developing with C# and Unity and trying to get testing workflow done in Unity. I plan to use the internal Unity test runner as testing framework and NSubstitute as mocking tool. I also know that Unity version that have Scripting runtime 4.x equivalent supports .Net 4.x and netstandard 2.0 compatible library from an article on Microsoft Docs (link) This may seem as a stupid question to ask, but what does that support for .Net 4.x and netstandard 2.0 in API compatibility level means when we imported the external DLLs? Do I need to copy the .dll from a package that targets netstandard 2.0 if I use that same API compatibility level in the setting or can I also use net45 or net46 build with that same choice of API compatibility level? Any help or insight is much appreciated.