Although the words displayed on a computer screen appear in the language selected by the user, the computer does not understand English, French, or any other modern language. At its most basic level, the computer "speaks" only in binary, which is a language consisting of only two characters: "1" and "0." A content format is the middle man which sits between the computer's natural code language and the output text displayed onscreen, converting the information from one to the other, smoothing interaction between man and machine.
Think of the role of the content format as that of the interpreter who might help you communicate with someone who speaks a foreign language. When typing information into the computer, the content format alters the typed characters to a format the computer will understand. Additionally, when the computer receives raw data from a webpage or program, the content format translates those 1's and 0's back into text, displaying all of the salient information provided by the webpage or application. Without the content format, the information on the screen would be just a nonsensical readout of binary computer code.
Displaying text is the easiest way to understand a content format, but it is also used when displaying other types of information on the computer, such as audio and video files. Although it might be hard to conceptualize, audio and video information on the computer are transmitted through the same binary set of 1's and 0's as everything else. The content format takes those characters and converts them into sounds and pictures, routing the information through the video and audio cards on the computer. Similarly, when saving a song or image to the computer, the content format stores that information on the hard drive in binary format, providing a near-instantaneous "translation" each time the file is selected.
A content format can also be used to protect sensitive data by encrypting it. Encryption is the process of encoding data; instead of translating it directly into the binary language, it translates the information into a code. For example, think of a basic encryption code where numbers represent letters: where a=1, b=2, and so forth. The content format does the same thing, only on a much more complex scale, protecting the information against accidental or intentional interception by unauthorized parties. The strength of an encryption is typically measured by its bitrate, so a 32-bit encrypted file is stronger than a 16-bit encrypted file.