Buzz! Laughably WRONG answer.
Megahertz is indeed a measure of frequency and speed. Consider your first computer running at less than 10 MHz. It was replaced by a computer running at a far faster speed.
We have one large electromagnetic spectrum. Radio, light, sound, RF, (Radio Frequency) all sit along side each other in a very long, continuous space called the Electromagnetic Spectrum.
At 3.800 MHz, I can use it to communicate with mates on CW; as frequency increases, "speed" increases until we reach a point where the radio waves can cook an egg in your microwave oven.