What is “gof” and how does it relate to design patterns?

GOF refers to the gang of four pattern that are generally consider the basic for all the other patterns. Design pattern are basically provide the solution to the software design to resolve all problems that are associated with the development of real world applications.

GOF Design pattern implemented the parts of the re-usable object oriented software applications. The main aim of design pattern is to pass all the structural design pattern. Design pattern is the most powerful and helpful tool for the software developer and architecture.  

since it can be assumed that what aslam is making is a template by compiling all the commonly used excel formatting in several worksheets in an excel document, aslam can choose to save it using the .xltx or .xltm format instead. thus, aslam can distribute the templates he has made to his team members in an easier manner.