Explain the use of checksums and CRC (Cyclic Redundancy Check) in ensuring data integrity during communication.

Checksums and Cyclic Redundancy Checks (CRCs) are used to ensure data integrity during communication by providing a means to detect errors that may occur during transmission. Data integrity refers to the accuracy and consistency of data. During communication, data can be corrupted by noise, interference, or other factors. Checksums and CRCs are error detection codes that are appended to the data before transmission. A checksum is a simple error detection method that involves summing the data bytes and then transmitting the sum along with the data. The receiver calculates the checksum of the received data and compares it to the received checksum. If the checksums match, the data is assumed to be error-free. If they don't match, the data is considered corrupted and is discarded or retransmitted. A CRC (Cyclic Redundancy Check) is a more sophisticated error detection method that uses polynomial division. The data is treated as a large binary number, which is divided by a pre-defined polynomial. The remainder of the division is the CRC value, which is appended to the data before transmission. The receiver performs the same division on the received data and compares the calculated CRC value to the received CRC value. If the CRC values match, the data is assumed to be error-free. CRCs are more effective at detecting errors than checksums, particularly burst errors (multiple consecutive bits in error). They protect against data corruption.