This document discusses an event called the Invasive Species Action Week held in California to raise awareness about invasive species and encourage public participation in preventing their spread. It defines invasive species as plants or animals not native to an area that can spread rapidly and negatively impact the local ecosystem. The document provides examples of invasive plants in California and how they are spread. It emphasizes that prevention is the most effective strategy for managing invasive species and provides over a dozen actions individuals can take to help prevent the introduction and spread of invasive species.