.NET

Maybe something to add to the side-bar?

The linked post doesn't seem like that good of a reference that I would put it in the sidebar. IMO it could be done better. But if you mean to say, something like it; yeah, the .NET environment is vast and can be confusing, especially when new to it. An overview or reference to one makes sense.

I suppose the term “.NET” encompasses both, but most of us that write and speak in this space tend to use “.NET Framework” for legacy, and “.NET” for modern .NET.

there’s the whole “.NET Core” thing

Before around net7, the open source cross platform non-framework dotnet was called Core. net6/7/8 is the .NET Core technology, but Core was dropped from the naming.

Now, .NET may refer to that modern dotnet tech, or .NET Framework. Presumably, the latter is referred to only in contexts where it's obvious that .NET Framework is meant.

and .NET Standard (2 versions). […] Are those relevant in the world right now, today? Hopefully not really!

.NET Standard is still relevant for libraries that target/publish for both .NET Framework and net6+. .NET Standard is the cross-platform baseline.