Webmaster Tools are online services provided by search engines to help website owners manage their sites' presence in search results. These tools offer insights into how a site is performing, including data on search traffic, indexing status, and any issues that may affect visibility. By using Webmaster Tools, users can submit sitemaps, monitor backlinks, and receive alerts about potential problems like broken links or security issues. This information helps website owners optimize their sites for better search engine performance and improve user experience.