What is checksum and how it works?

A checksum is a numerical value calculated from a data set, used to verify the integrity of the data during transmission or storage. It works by applying a specific algorithm to the data, producing a unique hash value that represents the original content. When the data is received or read, the checksum is recalculated and compared to the original; if they match, the data is likely intact, while a mismatch indicates potential corruption or alteration. Common checksum algorithms include CRC, MD5, and SHA.