What’s a GNU/Linux distribution?

By now, almost everyone who has a computer has heard about something called “Linux”. Usually, what they hear goes something like this—“Well, Linux is free, but it’s very difficult to use. Don’t try it unless you’re a computer expert”. There is also generally talk about how “Linux” is incompatible with equipment like digital cameras, printers, and games. In short, “Linux” is generally thought to be a free but experts-only operating system. Fortunately for those of us who aren’t computer experts, almost all of these “facts” about “Linux” are completely wrong.

What’s a GNU/Linux distribution?