Answer:

Hexadecimal numbers are numbers in base sixteen. They are expressed using groupings of units, sixteens, (sixteens)₂ and so on. In addition to the digits 0,1, 2, …, 9, the letters A, B, C, D, E and F are used to represent the numbers ten to fifteen.

For example, the hexadecimal number 23D stands for 2 x 256 + 3 x 16 + 13 in base ten which is 573.

Hexadecimal numbers are used in electronics and information technology (for example, in specifying background and text colours on Internet web pages). They are more compact than binary numbers since they use fewer heights but they can easily be converted into binary numbers, and vice versa.

For example, to express 47_sixteen as a binary number, write each digit as a binary number with four columns and then delete any zeros on the left.
47_sixteen = 0100_two | 0111_two = 1000111_two.