Private Assembly : Private assembly is access only the one application.

Public Assembly : Public assembly can access  more than one application and that assembly resides in GAC. We have followed some exercise to create a public assembly . Which is described below.

1. Create a strong naming for that assembly.
2. GACUtil.ext use to install in the widows system. Dot net have followed some
 algorithm to deploying a assembly in GAC.When ever that assembly will referred then again same algorithm comes in picture.

Private AssemblyThe Assembly that is local to the particular folder is called Private Assembly
The disadvantage is that each time a copy of the Assembly is created which in turn occupies more memory and reduces the performance

Shared AssemblyWhen we maintain one copy of the Assembly for set of applications through out the system it is called Shared Assembly
More memory usage can be reduced by this concept

So here comes the concept of public key and version number to maintain unique ness of the Assembly for particular application.