The operating system can be categorized into three kinds, namely desktop operating system, network operating system and embedded operating system. Interestingly, Disk Operating System (DOS) is considered to be the first operating system which was used in IBM compatible desktop computers in 1980s. The primarily used computers were mainly utilized for teaching programming with the use of language called BASIC. The early computer programs were written in code. However, in later stages, a compiler and an interpreter were used that converted the source code into machine language that could be comprehended by the Central Processing Unit (CPU). In the year 1980, students were able to write programs and store them upon inexpensive tapes. The tapes were similar to those used for recording devices. This type of storage was called as sequential storage device as the data had to be stored and accessed in sequence. Later, such storage was also called as the secondary or permanent storage. At present, there exists various types of operating systems. however, it can be broadly classified into two groups which are open-source operating systems and proprietary operating systems. As the name suggests, proprietary operating systems are primarily possessed by a corporation and such OS are controlled by the individual or the corporation itself. On the contrary, open-source operating systems allow everyone to change the source code and thereby the OS. For instance, LINUX is considered to be an open-source operating system. In 1980s, the American Standard Code for Information Interchange (ASCII) was created. Accordingly, ASCII uses 8 bit code that could have 2 to 8 power possible bits. These orderings could represent 256 different characters. The most popular word processors used in mid 80s, prior to the development of WINDOWS was WORDPERFECT. WORDPERFECT was written on DOS based operating system but it was extremely slow to move in WINDOWS system, as a result of this the word processor popularity reduced over a period of time. In fact, WORDPERFECT was made compatible with LINUX version but it could not compete with the open-source word processors. There are many software programs which are built to perform specific tasks while certain software are built for general purposes, i.e. programs that have a few specific capabilities, but these software programs are not meant to perform any specific purpose. For instance, spreadsheets can be utilized for keeping monthly records of an individual’s income as well as it can be used to determine or calculate the marks of students obtained in an examination. 2. A. Netcraft.com Netcraft is an internet service providing company. It is located in Bath, England. The company obtains its revenue from the internet security services that it provides along with research and analysis of various aspects of the internet and by advertisements that it accepts to publish on the Netcraft website (Net Craft Ltd., About Netcraft) According to a survey conducted by Netcraft on web server, there was a decrease of 8M sites since last month i.e. August 2012.