BleachBit is a free and open-source software designed to clean up unnecessary files from a computer. It helps users free up disk space by deleting temporary files, cache, and other data that can accumulate over time. This tool is available for various operating systems, including Windows and Linux. In addition to file cleaning, BleachBit also offers privacy features by wiping out traces of online activity, such as browser history and cookies. Users can customize the cleaning process by selecting specific applications and file types to target, making it a versatile option for maintaining system performance and privacy.