Checksum
A checksum is a small-sized datum derived from a block of digital data for the purpose of detecting errors that may have been introduced during its transmission or storage. It is computed by applying a mathematical algorithm (like CRC, MD5, or SHA) to the data, producing a fixed-length value that acts as a digital fingerprint. Checksums are widely used in networking, file integrity verification, and data security to ensure data has not been corrupted or altered.
Developers should learn and use checksums when they need to verify data integrity, such as ensuring downloaded files are complete and uncorrupted, validating data packets in network communications, or detecting accidental changes in stored data. They are essential in cybersecurity for verifying software downloads, in distributed systems for consistency checks, and in backup systems to confirm data hasn't been tampered with, helping prevent errors and security breaches.