Disk cleanup tools are software applications designed to free up space on a computer's hard drive by removing unnecessary files. These tools can identify and delete temporary files, system cache, and other items that accumulate over time, helping to improve system performance and efficiency. Many operating systems, such as Windows and macOS, come with built-in disk cleanup utilities. Users can also find third-party options that offer additional features, like scheduling regular cleanups or providing detailed reports on disk usage. Regular use of these tools can help maintain optimal system performance.