Hexadecimal is very common in computing because 2 hexadecimal digits code 8 bits (1 byte) and conversions between hexadecimal and binary are very easy (see "How to convert hexadecimal to binary ?" and "How to convert binary to hexadecimal ?").

In networks, for example, we use the hexadecimal notation for Media Access Control (MAC) addresses coded on 48 bits, i.e. 12 hexadecimal digits.