This document summarizes information about jet pumps, including: 1) It classifies four main types of jet pumps based on application and size: deep well, shallow well, convertible, and miniature. 2) It describes three common types of impellers - open, semi-closed, and closed - and their structural characteristics and typical uses. 3) It explains the three stages of jet pumps: single-stage pumps with one impeller and a lift of 125 meters, double-stage pumps with two impellers and a lift of 40-160 meters, and multi-stage pumps with two or more impellers to increase lift. 4) It provides a brief definition of casing and coupling components