This is an EBook of Computer science and engineering field to find complexity of algorithms. Algorithm is a step by step process to solve a problem. Algorithm is an advance preparation of a program. Numbers of algorithms are possible to solve a single problem, among all algorithms some algorithms will solve a problem efficiently. So with the help of analysis and design of algorithms we can find better algorithms. This is a very simple EBook, a person can learn the techniques only with the reading of this EBook. Only read and learn.