This document discusses Greek and Latin roots that are commonly found in English words. It provides examples of roots such as "hydr" meaning water, "aqua" meaning liquid, "mar/mer" meaning sea, "vis/vid" meaning see/look, "aud" meaning hear, "phon" meaning sound, "mem" meaning recall, and "ology" meaning study. For each root, it lists several English words that use that root and defines their meanings.