1 - The Computer 

The word computer has its origins in the word compute, which means to perform calculations. Therefore, a computer is essentially a device that essentially performs calculations. Ever since computing began with counting, there has been a need for faster computing methods and faster computing tools. This is mainly due to numbers playing an important role in our daily activities. One of the first known tools used to speed up calculations was the abacus. The abacus, a device consisting of sliding beads on rods, allowed the user to perform computations faster than pencil and paper methods. With the advancement of various branches of mathematics and the sciences, the need for faster computing methods and computing tools also grew. First attempts at creating computing tools were focused on mechanical devices. The earliest of these being the Pascal adding machine followed by the Babbage machine. These machines were made with mechanical gears and levers, and were not very effective as a computing tool. With the lack of substantial progress with mechanical devices, the focus of research was shifted to other approaches.

Following the work of George Boole in the early 1930's, the focus was shifted from mechanical devices to electrical devices. This was the first major step that led to the development of the electrical computer. Using electrical devices in computing turned out to be an effective approach for performing calculations and making decisions. This approach to computing has proven to be effective and has led to a fast pace of development of modern day computers. Even though computers today are advancing very quickly in terms of speed and capability, the underlying principles of the computer remain the same. These principles are the focus of this online resource (formerly a book).

Compared to the computing devices of the past, computers of today seem to perform very little mathematical calculations. But this is deceptive. Our interactions with the computers of today reveals very little of the calculations that are being performed to process these interactions. The graphics, the text, the video, the audio and everything else that the computer uses to interact with us are all essentially based on numbers and different types of calculations. So, ultimately, the computer of today is still essentially a calculating device!