The Google Panda update was launched in August 2011 to reduce rankings for low-quality websites and increase rankings for high-quality websites. The update targeted issues like duplicate content, low-quality inbound links, irrelevant advertising, and keyword stuffing. To protect their sites from being affected, website owners should focus on optimizing for quality by ensuring original and error-free content, removing duplicate content, avoiding keyword stuffing, and obtaining links from high-quality sources.