This document provides an overview of digital data representation in computers. It explains that computers can only process data that is represented digitally using binary digits (bits) of 1s and 0s. Bytes made up of 8 bits can represent different characters using codes like ASCII. Common file types indicate whether the file contains program code, text, images or other user data. The document guides the reader through these concepts over multiple pages with examples and explanations of binary numbers, bytes, ASCII codes and file formats.