Types of Assembly

Private Assembly: This type of assembly is used by a single application. It is stored in the application's directory or the applications sub-directory. There is no version
constraint in a private assembly.

Shared or Public Assemlby: A shared assembly has version constraint. It is stored in the Global Assembly Cache (GAC). GAC is a repository of shared assemblies maintained by the .NET runtime. It is located at C:\Windows\Assembly OR C:\Winnt\Assembly. The shared assemblies may be used by many applications. To make an assembly a shared assembly, it has to be strongly named. In order to share an assembly with many applications, it must have a strong name.