it is a compact representation of binary. Hex (and Octal) can be used when the actual bit pattern is important, as in handling computer instructions, amd packed data such as single bit flags (true/false, on/off) are packed into a byte/word. Usually when numbers are stored, some form of decimal numeric representation will be used, but hex may also be used in technical situations - like colour codes in HTML as they're more compact

Hexadecimal numbers are used in MAC addresses (hardware addresses) in computers. This gives an unlimited number of possible combinations to computer manufacturers. That way each PC in the world has a unique identifier. Esuka Endeley Hexadecimal is a number system using Base 16. It uses the digits from 0 to 9 and the letters from A to F, A=10, B=11, C=12, D=13, E=14, F=15. It enables very large numbers to be written with fewer characters. As computers have very large memories, addressing specific parts of them becomes a big task. Hexadecimal is used as a way of doing so. Sometimes if your computer crashes you will see an error message showing a number with letters in it. Those letters are always between A and F. Basically what it is saying is that there was a problem in memory at this point. Hexadecimal is used in many other ways in computers. One very common purpose is for colour codes in web pages. 6 digits are used, with 2 representing the amount of Red, 2 the amount of Green and 2 for the amount of blue. So if you want a lot of Red, but not much blue or green as a mix for your colour, the code could be something like FF0502. FF represents 255. If you do a web design course, specifically learning to use HTML for creating colours on your pages, you will learn more about this.