What is the difference between *which version of the framework is running* and *which version of the runtime is running*?

Question

In this post, @kbrimington mentions that there is a subtle difference between which version of the framework is running and which version of the runtime is running.

What is the difference exactly?

Answer 1

Here is a quick breakdown that might give you the information you want. It can be confusing, but it is worth your time to understand the difference between all three and how they differ and interrelate.

CLR    .NET    C#  
----   ----    ----  
1.0    1.0     1.0  
1.0    1.1     1.0  
2.0    2.0     2.0  
2.0    3.0     3.0  
2.0    3.5     3.0  
4.0    4.0     4.0  
4.0    4.5     5.0