Parameter
All parameters are describers for basic objects. They are things that can go up or down if they are affected by processes. Usually, its possible to think of parameters as something that you can use a number for. The parameter box should be used when "amount" or "level" doesn't work for the thing you want to describe.

For example, you might want to talk about something's density or size. Since that isn't an amount or a level, you could use parameter for it.