How Digital Computers Use the Binary System.
It is extremely common for digital computers to use the binary system. Computers represent values using two voltage levels. Using the values of zero and one, computer makers represent these two levels of voltage. All of the tasks that a computer perform, are simply manipulations of numbers that have been converted to the binary system, and are represented by the voltages. In order to represent negative numbers, the last (left-most) bit is reserved to indicate the sign of the number. Binary logic also uses these two digits in its system. The binary system was chosen in computer checks the bit value by using current. With a binary system only the presence or absence of the current needs to be checked in order to obtain an outcome processes possibilities or respondence to a command, while with a decimal system, ten different current intensities would need to be checked in order to obtain an outcome.
The word digital has become synonymous with the word binary, because computers are and were always familiarized by most people as process information coded as combinations of binary digits. Something is considered digitized when there is a conversion of any analog or other continuously varying signal, and in the lines of a drawing or a sound signal; which then are converted into a series of discrete units represented by the digits 0 and 1. For example, a drawing or photograph can be digitized by a scanner that converts lines and shading into combinations of zeros and ones by sensing different intensities of light and dark. Analog-to-digital converters are commonly used to perform this translation. Digital representation represents a value as a coded number, the range of values represented can be very wide, although the number of possible values is limited by the number of bits used (US Byte, 1999).
Computers are often classified by the number of bits they can process at one time, as well as by the number of bits used to represent addresses in their main memory or RAM.