TITLE: Error-correcting codes used in real life
QUESTION [13 upvotes]: I am very interested in coding theory and I wonder if there is a particular kind of codes used in practice. 
For example I read that Reed-Solomon codes are often used for encoding data on a compact disc. 
In particular I would like to know which kind of code is mostly used in real life and in which contest. I know that it is not a specific question but I'm really curious to know how coding theory is used in current technology.
Moreover I'm also interested in knowing which is more or less the usual length of a code used in practice. 
Thanks a lot for the answer

REPLY [3 votes]: To give a totally different example, codes have also been used for betting systems that guarantee at least one bet with many matches while placing relatively few bets