This document discusses weeds, their identification and control. It defines weeds as plants in the "wrong" place that compete with cultivated plants. Weeds reduce crop productivity and visual appeal by competing for resources. They can also host pathogens and pests, allowing them to overwinter and rapidly infect crops. Weeds are classified as ephemeral, annual or perennial based on their lifespan. Control methods include physical removal, herbicides, and cultural practices. Herbicides are contact, residual, translocated, or selective depending on their mode of action and appropriate uses are outlined.