Sometimes, it is useful or necessary to tell an application to use a specific version of an assembly. These policies are established by entries in the configuration files.
A policy can state that:
“References to assembly XZY, version 1.0 should be bound to version 1.2”
When the runtime needs an assembly, these policies are reviewed to determine if the runtime should use the originally targeted version or a different version of the assembly.
For detailed information about configuring version policy, please look at Versioning in NGWS.