What Use Is An F-call?

What use is an F-call? From DC to Daylight is a term that until I became an Amateur, I'd never heard of and since becoming licensed I've bumped into it more than a couple of times. Once you sit and think about it, the notion, from DC to Daylight makes perfect sense, but what does it mean? I'll start off with that I'm not talking about Cheap Therapy for your Inner Problem Child - the Rock band based in San Jose, California. So, DC, or Direct Current, as opposed to AC, or Alternating Current does not change frequency, that is, the positive and negative poles never swap over, so the frequency that they switch at is 0Hz or zero times per second. If you reverse the poles, the frequency at which you do that, say flick a switch once every second, the frequency is 1Hz. AC does it 50 or 60 times per second, or 50 or 60 Hz. As you keep increasing the frequency, you'll come past 160m, just below 2MHz, 80m around 7MHz, etc, onto 2m around 145MHz, 70cm and up to WiFi at 2.4GHz, then 5.8GHz, eventually, you'll get to