Computers store data in binary, you maybe asking what is binary. Binary is a number system composed of only two digits, "0" and "1", which can represent all values, also referred to as base-2 number system. Below is a table which can be used for turning denary number ( 1,2,3,4,5 etc..) into binary.

Computers store data in binary because it is a simple and efficient way to represent data using only two states, or "bits." Each bit can represent either a "0" or a "1," which can be thought of as "off" and "on".