Why do computers use binary?
"Number" is an abstract symbol that expresses the number or order of things. If there are only a few things, you only need to use a few symbols to record these "quantities", such as 1, 2, 3, etc. However, humans have long realized that the "number" of things is actually endless. Since there is no way to create infinite numbers, how to use a limited number of symbols to record infinite numbers has become a necessary but extremely difficult thing.
One of the greatest creations of mankind in the history of counting is the carry system or bit value system. In addition to decimal, the main carry systems in common use in the world are binary (common to computers), decimal (very popular among the British) and hexadecimal.
Binary is the simplest carry system. It was introduced in 1678 by the German mathematician Leibniz to meet the needs of the computer he invented. In binary, every 2 enters 1, so only two basic symbols 0 and 1 are needed. Second and third are denoted 10 and 11 respectively, and fourth is denoted 100, and so on. For example, 100101 in binary represents 37 in decimal. Although there are few binary symbols, compared with other carry systems, it requires more bits to express the same number. For example, 9 has only one digit in decimal, but has four digits in binary, which is denoted as 1001.
Using binary to express numbers has many digits, which is not intuitive in terms of form, but it has many advantages in calculation: it has only four addition and multiplication formulas: 1+1=10, 1+0=1, 0+1=1, 0+0=0, and 1×1=1, 0× 0=0, 0×1=0, 1×0=0; while in decimal, there are a total of 100 corresponding formulas.
Due to the few binary symbols and simple arithmetic rules, Leibniz adopted binary on the computer. The reason why modern electronic computers still use binary is that phenomena with two distinct states such as energization and disconnection of circuits, charging and discharging of capacitors, etc., are abundant, and these can be used to represent the two symbols of binary 1 and 0.