The ASCII character set is the most popular one in common use. People will often refer to a bare text file without complicated embedded format instructions as an ASCII file, and such files can usually be transferred from one computer system to another with relative ease. Unfortunately there are a few minor variations of it that pop up here and there, and if you receive a text file that seems subtly messed up with punctuation marks altered or upper and lower case reversed, you are probably encountering one of the ASCII variants. It is usually fairly straightforward to translate from one ASCII variant to another, though. The ASCII character set is seven bit while pure binary is usually eight bit, so transferring a binary file through ASCII channels will result in corruption and loss of data. Note also that the ASCII character set is a subset of the Unicode character set.