Where is version information stored of a assembly ?

All versioning of assemblies that use the common language runtime is done at the assembly level. The specific version of an assembly and the versions of dependent assemblies are recorded in the assembly's manifest. The default version policy for the runtime is that applications run only with the versions they were built and tested with, unless overridden by explicit version policy in configuration files (the application configuration file, the publisher policy file, and the computer's administrator configuration file).

The runtime performs several steps to resolve an assembly binding request:

1. Checks the original assembly reference to determine the version of the assembly to be bound.

2. Checks for all applicable configuration files to apply version policy.

3. Determines the correct assembly from the original assembly reference and any redirection specified in the configuration files, and determines the version that should be bound to the calling assembly.

4. Checks the global assembly cache, codebases specified in configuration files, and then checks the application’s directory and subdirectories

Version Information
Each assembly has two distinct ways of expressing version information:

The assembly's version number, which, together with the assembly name and culture information, is part of the assembly's identity. This number is used by the runtime to enforce version policy and plays a key part in the type resolution process at run time.

An informational version, which is a string that represents additional version information included for informational purposes only. Assembly manifest stored this information.