Assemblies are a fundamental part of programming with the .NET Framework. An assembly performs the following functions; contains code that the common language runtime executes, forms a security boundary, acts as the unit at which permissions are requested and granted, forms a type boundary, forms a reference scope boundary, forms a version boundary, and forms a deployment unit. Creating an assembly can be done programmatically, and that creation of an assembly is done with the help of various classes like the AssemblyBuilder, ModuleBuilder, AppDomain, AssemblyName, etc.

The compiler differentiates an assembly from a satellite assembly by an attribute called AssemblyCultureAttribute. This attribute will be filled with the appropriate value to identify the assembly as a normal assembly or a satellite assembly.