Reed-Solomon codes are a type of error-correcting code used to ensure data integrity in digital communications and storage. They work by adding extra information, or redundancy, to a message, allowing the original data to be reconstructed even if some parts are lost or corrupted. This makes them particularly useful in applications like CDs, DVDs, and QR codes. These codes are based on polynomial mathematics and can correct multiple errors in a block of data. By dividing the data into smaller pieces and encoding them, Reed-Solomon codes can identify and fix errors, making them a reliable choice for protecting important information in various technologies.