Convolutional codes are a type of error-correcting code used in digital communication systems to improve the reliability of data transmission. They work by processing input data through a series of memory elements and generating a sequence of output bits, which are derived from the input bits and their previous states. This allows the receiver to detect and correct errors that may occur during transmission. These codes are often implemented in conjunction with Viterbi algorithms, which are used for decoding the received data. By analyzing the received bit sequence, the Viterbi algorithm can identify the most likely original data sequence, effectively correcting any errors introduced during transmission.