Error detection and correction

Error detection and correction is about methods to make sure that information or data is not corrupted, and still makes sense. The techniques help reliable delivery of digital data over unreliable communication channels.
Detecting an error.
There are different ways to make sure an error can be detected. This is done by adding more data or information to the data transmitted. Adding more data than needed is called redundancy.
Correcting an error.
There are two main ways to correct an error: