Explanation:

- CPS (Characters Per Second): Refers to the speed of impact printers, like dot matrix printers, which print characters one at a time.

- LPM (Lines Per Minute): Measures the speed of printers that print entire lines at once, such as line printers.

- PPM (Pages Per Minute): Used for modern printers like laser and inkjet printers, which print entire pages quickly.

- All of the above: Different types of printers use different units to measure speed, reflecting how they function.