I have five types, most people think four. The fifth is quite rare, humans seek to learn more. Sometimes I’m obvious, red, swollen, foul. Yet other times I’m hidden, no symptoms at all. Treat me too lightly, I may come back strong. Ignore me too long, and things can go wrong.

I keep your history or become a room. Hidden in the roof, I am the last floor of some homes.

Jeff Spicoli learned: No me? No service!

We are very little creatures; all of us have different features. One of us in glass is set; one of us you'll find in jet. Another you may see in tin, and a fourth is boxed within. If the fifth you should pursue, it can never fly from you. What are we?

I’m a tool, a toy, a mechanical device. I’m sometimes used only once or twice. My uses are plenty, many and more. I collect them and show them, I’m told I’m a bore. Remembering their names is quite the chore.