Questions

Iteration means doing something again and again, repeatedly,... 

Hence, looping is a process of repeating a method and so it is similar in meaning to Iteration.

GUI stands for Graphical User Interface.

A Graphical User Interface is a computer interface that allows users to interact with a device through graphical elements such as pictures and animations, as opposed to text-based commands.

The MESI protocol is also known as illinois protocol due to its development the University of illinois at Urbana-Champaign and MESI is a widely used cache coherency and memory coherence protocol.

MESI is the most common which supports write-back cache. its use in personal computers became widespread with the introduction of intel's pentium processor to "support the more efficient write-back cache in addition to the write-through cache previously used by the Intel 486 processor"/