.NET platform, .NET environment or .NET framework which is correct? And what's the difference between platform/environment/framework?

In some documents (i.e. ECMA-334) the name of '.NET framework' is used, but in other documents (in many books), '.NET platform' is used. I saw someone refer .NET as .NET environment.

• Which one is correct nomenclature for .NET?
• In general, what's the difference between platform/environment/framework?

ADDED

It's not easy to see that those three names are the same as

• We don't say Qt platform, but we say Qt framework
• We say cross platform to indicate the interoperability upon many OS, but not cross framework.

If people just say .NET environment, .NET platform, and .NET framework as the same meaning only for the .NET, I can buy that.

These are semantically identical. Usage depends only on the context where it is used:

• You build code using .NET framework (equals .NET libraries)

• The code runs on the .NET platform (in the CLR)

• You need to install .NET environment (.NET framework redistributable)

None of them is the only "correct one" while all are correct for all scenarios.