Understanding ASCII and Other Forms of Data

Using the ASCII table

If we give each letter of the English alphabet a numerical value, we could represent text with numbers. We could, for example, say that A = 1, B = 2, and so on. The computer does not use these values for the letters, but instead, it can either use something that is called the ASCII (American Standard Code for Information Interchange) table (pronounced as-key) or another representation that is called Unicode. It isn’t important to understand exactly how they work; the only thing we need to understand is that a number can represent every character. This number can then be looked up using either the ASCII table or Unicode.

The ASCII table uses one byte (8 bits) to represent different characters. The table starts with characters that are nonprintable. Eventually, it reaches the characters in the English alphabet. So, A, for example, is 65, B is 66, and so on. 255 characters won’t take us far due to there being lots of different alphabets around the world, and we also want to represent other symbols. That’s why we also have Unicode. Its mapping to individual characters is not as direct as it is in the ASCII table, but all we need to know right now is that with Unicode, we can use numbers to represent characters.