Currently the computer has occupied all the places and soon all the work will be computerized. In this situation this book given some basic education about computer, what are characteristics of computer, how it functions, what are terms used for its devices, versions of computers we are using, and also we are in need of accessing basic software in our day to day life. Some software applications like MS-Word, MS -Excel, MS ¿Power point, MS ¿Access are some that will be discussed. The uses of multimedia play an important role in our life. Without knowing about those elements we are using here, we can get ideas about multimedia elements and its applications. CATT Plays a vital role in online education. The benefits of using CATT Applications are that it tells how the computer teaching and testing will be done. Introduction of internet, types and its applications will be easily understandable and learnable. Another thing that will be discussed is how when handling large amount of information we can easily handle and get conclusion with the help of statistical software package. Finally, how these computer applications will be useful for health care professionals is pointed out.