|Computer information is often called digital because all of the information inside it is represented as numbers.
The original meaning of “digit” is “finger,” and since people often count using their fingers, the term digit also came to be applied to numbers. All of the numbers in a spreadsheet, all of the text characters in a Word document, all of the pictures and sounds stored in a computer, are ALL represented as numbers.
The number system that you use is base 10 (since people have 10 fingers, this works out well for them). When you write the number 1853, for example it means:
Each digit (0-9) within a base 10 numbers is multiplied by the power of ten corresponding to its position. Notice that each digit place has 10 times the value of the digit place to the right of it.