Hexadecimal (also known as hex) is a numbering system used in computing and digital electronics. It is based on a sixteen-digit binary code that can represent a wide variety of values. Hexadecimal is widely used for encoding color values, as well as a shorthand notation for bytes and computer memory addresses.
In the hexadecimal numeral system, each digit has a base value of sixteen. This is in contrast to decimal (base 10) and binary (base 2) numbering systems, where each digit is a power of 10 and 2, respectively. Because sixteen is a power of two (2^4), hexadecimal numbers are represented using four binary digits (bits).
The name “hexadecimal” comes from the Greek words “hex” meaning “six” and “decimal” meaning “ten”. When expressed in decimal form, each place value corresponds to a multiplication by a power of sixteen: for example, the seven-digit number 3A8 would represent 3 x 16^6 + 10 x 16^5 + 8 x 16^4, or 107,216 in decimal form.
As computers store data in binary form, hexadecimal is often used to represent binary data more easily. Hexadecimal numbers can be used to represent constants, processor instructions, numerical values, memory addresses, and other data. The hexadecimal notation is especially useful for displaying binary-encoded data in a more human-readable form. For example, the hexadecimal representation of the ASCII text “HELLO WORLD” would be 48 45 4C 4C 4F 20 57 4F 52 4C 44.
Hexadecimal is often used to notate web colors, where each color channel (red, green, and blue) is represented by two hexadecimal digits between 00 and FF. For example, the color white is represented by the code FFFFFF, while black is represented by 000000.
In programming languages such as C and Java, it is possible to represent Hexadecimal values using the prefix ‘0x’ (e.g. 0xff = 255 in decimal). Furthermore, some programming tools and calculators can convert between hexadecimal and other number-systems.
