Most computer users understand that you need an operating system to use a computer practically, even if it is not clear why. But many users don't.
This page briefly describes every file format (or actually the file name extensions for the formats) that we have been able to learn about.
Me: "How can I help you today, ma'am?" Client: "Is e-mail internet"? Me: "I beg your pardon?" Client: "Is e-mail on the internet? I have no internet, can I still read my e-mail?" Me: "Well yes, you...