ab_n00b 0 Newbie Poster

Can anybody tell me what is the difference between those 2 algorithms ? I've done a few research and it says Damerau-levenshtein enables transportation characters which levenshtein does not support. I wanna know how it does. Damerau algorithm on wikipedia isn't very clear. Please somebody point me to a good site in order to understand more of it. I'm writing a paper for those algorithms and I need to make a comparison between 'em. Thanks all in advance.