Transposon: A transposon is the specific segment of DNA that moves during transposition. It's like the sentence you're moving in your word document.
Jumping Gene: This is another name for a transposon because it 'jumps' from one location in the genome to another.
Insertion Sequence: An insertion sequence is the simplest type of transposon which only contains genes involved in transposition. It's like having just enough text for your cut-and-paste operation.