Error detection and correction is done

• Networks must be able to transfer data from one device to another with complete accuracy.
• An error occurs when a it is altered between transmission and reception (1 is transmitted and 0 is received, and vice versa)
• For reliable communication, errors must be detected and corrected.
• Error detection means deciding whether the received data is correct or not without having a copy of the original message.
• Error detection and correction uses the concept of redundancy, which means adding extra bits for detecting errors at the destination.
• These redundant bits are added by the sender and removed by the receiver.

The error detection methods include:

• VRC (Vertical Redundancy Check): It is an error-detecting code commonly used in digital networks and storage devices to detect an error in data sent by the sender.
• LRC (Longitudinal Redundancy Check): It is an error-checking method used on an eight-bit ASCII character
• CRC (Cyclic Redundancy Check)
• Checksum