CLASS I TRANSPOSONS. “Today, scientists know that there are many different types of TEs, as well as a number of ways to categorize them. One of the more common divisions is between those TEs that require reverse transcription (i.e., the transcription of RNA into DNA) in order to transpose and those that do not.”
http://www.nature.com/scitable/topicpage/transposons-the-jumping-genes-518