EQ

Shelving EQ - creates shelf so that any frequencies below or above the shelf get eliminated

Bell EQ - takes certain point in the frequency spectrum and either boosts it or cuts it

Graphic EQ - like the calliope mixer - take one frequency and change it (there's a bunch of little sliders)

Parametric EQ - low Q picks up a lot, high Q picks up a very specific point. allows you to change a lot.

http://www.independentrecording.net/irn/resources/freqchart/main_display.htm: