Deployment and the Global Assembly Cache
The global assembly cache is a machine-wide code cache provided by the .NET Framework that is used to store assemblies that need to be shared by several applications on the computer. In order to be installed to the global assembly cache, the assembly must be strong-named.
To install an assembly to the global assembly cache, add the assembly or the project output group for the assembly to the Global Assembly Cache folder in the File System Editor.
The Global Assembly Cache folder is unlike the other folders in the File System Editor. It has no properties that are settable, and you cannot create shortcuts to the folder or to assemblies in the folder.