1. There are two types: soft and hard. The soft style is similar to a baitfish profile and rigged with a large worm hook. Example: Slug-Go. Hard jerkbaits resemble more of a minnow baitfish. Examples are a Rapala or Smithwick Rogue. Both style lures are fished by twitching or jerking the lure forward, hence the name.
2. a lipped, minnow shaped plug normally retrieved with a jerking motion of the rod tip