Relationship Between CLR and .Net Framework Versions

It depends upon CLR for .net framework we are using.

1. NET Framework 2.0, 3.0, and 3.5 include CLR 2.0.
2. NET Framework 4, 4.5, and 4.5.1 include CLR 4.0
3. CLR 3.0 does not exist
4. Application developed in 2.0,3.0 can run in 3.5 framework because target CLR is same

But application developed in 3.0 will not run on 4.5 framework because now target framework is different (CLR4)

NET Framework 1.0: "v1.0.3705"

• .NET Framework 1.1: "v1.1.4322"
• .NET Framework 2.0, 3.0, and 3.5: "v2.0.50727"
• .NET Framework 4 and 4.5 (including point releases such as 4.5.1): "v4.0