I can only give you a basic explanation:

The trottle actuator is just the butterfly valve in the throttle. In the old days there was a cable connected from the gas pedal to the valve. The 1998 has an electronic (motor operated) one. I don't know about 1994.

The MAF sensor measures the amount of air going in the engine. It sends this information to the ECU, which then controls the injectors to add the correct amount of fuel.

You didn't ask, but the O2 sensors then look at the exhaust and see if everything was done right, and help the ECU make any corrections needed to make the air/fuel ratio "perfect."

Search on surging idle, which is often caused by leaking or disconnected vacuum lines.

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1998 C230 330,000 miles (currently dead of second failed EIS, yours will fail too, turning you into the dealer's personal human cash machine)
1988 F150 144,000 miles (leaks all the colors of the rainbow)
Previous stars: 1981 Brava 210,000 miles, 1978 128 150,000 miles, 1977 B200 Van 175,000 miles, 1972 Vega (great, if rusty, car), 1972 Celica, 1986.5 Supra