Distortion and Overdrive
Distortion and overdive effects mimic the sound of a cranked tube amp by boosting the guitar's signal and causing the sound to "clip" which creates the distortion effect.
Compression
Compression is used to even out the over all volume of the guitar's input.
Tremolo
Tremolo is an effect created by the consistent alteration of the amplitude or volume of the guitar's sound signal.
Chorus
Chorus effects are produced by slightly delaying a sound signal and also altering its pitch while mixing it with the original sound signal.
Flange
Flange is an effect produced by two identical signals with one of the signals slightly delayed by a time that slightly, and continually changes.
Phasers
Phaser effects produce their sounds similarly to flange effects, but use phase shifting and replications of the original sound signal produce a "spacier" effect than the more natural tone of flange effects.
Delay and Echo
Delay and Echo effects repeat the guitars signal based on a time setting creating slap back and other delay and echo effects.
Reverb
Reverb effects alter the guitar's sound to recreate the subtle echoes of a room or other environment.
Pitch Shifters, Octave, and Harmonizers
These guitar effects alter the pitch of the guitar's signal to create their effect.
Wah-wah pedals
Wah-wah effects filter the frequencies of the incoming guitar signal to give it a distinctive, human-like sound when rocked back and forth.