The sound of a distorted guitar or bass is so recognizable to anyone who either listens to or plays music, you'd be hard pressed to find anyone unfamiliar with that sweet sonic bliss, heavy crunch, or nuclear meltdown that comes from a great distortion pedal.
While the classifications overdrive, distortion, and fuzz tend to be used interchangeably, there is a true difference and use for each of these pedals.
Overdrive pedals can create both subtle warm tones at lower volumes and nasty harsh tones as the volume increases. You'll find overdrives used more commonly with blues and rock.
Distortion pedals create that harsh overdriven sound at virtually any volume. This type of pedal is used mostly for heavier styled music like metal and punk.
Fuzz pedals are in a class by themselves. They distort to a sustain and introduce extra tonal frequencies. The fuzz is found in most styles of music due to its versatility and used for leads and solos.
Likewise, there's something to be said for the power unleashed by a clean boost that tickles the edge of distortion. Boost pedals do exactly as it sounds, they boost the signal going to your amp's gain stage.