The problem comes when the icon that it defaults to for printing is a right load, but the only way that envelopes can be loaded is in the center of the tray. I have an HP Colorlaserjet 3600 and an HP Officejet Pro 8600 and both load this way.
A technical definition of a function is: a relation from a set of inputs to a set of possible outputs where each input is related to exactly one output.
A function is a set of mathematical operations performed on one or more inputs (variables) that results in an output. For now, functions will take one or more real numbers as an input, and return a numerical output. In more advanced classes you'll learn about far more complex functions!