What role do Cyclic Redundancy Checks (CRCs) play in error detection?

Cyclic Redundancy Checks (CRCs) are a widely used error *detection* technique, though variations exist for correction. They work by treating the data as a large binary number and dividing it by a pre-defined generator polynomial. The remainder of this division is the CRC value. This CRC value is appended to the data. The receiver performs the same division and compares the remainder to the received CRC value. If they don't match, an error is detected. CRCs are computationally inexpensive and suitable for many applications, especially in network protocols and data storage.