Jug:  a very positive hold, large enough to get all fingers on or around it up to the palm

Pinch: a hold that is held by pinching between the thumb and fingers

Edge:  a hold that allows only a couple digits of all or a couple fingers to hang onto

Crimp:  similar to an edge but generally smaller and only thick enough to accomadate less than a single digit of all or one finger

Sloper:  a hold that is held onto by just friction of the fingers and palm, nothing to actually grab onto

Slimper or Sledge:  a small hold that is like a crimp, but it is not postive; a cross between a crimp and a sloper

Pocket:  a hold that has a hole in it that fingers are inserted in.