Transposons, also known as "jumping genes," are segments of DNA that can move within a genome. They can insert themselves into different locations in the DNA, which can lead to mutations or changes in gene expression. Transposons are found in many organisms, including plants, animals, and bacteria, and play a role in genetic diversity and evolution. There are two main types of transposons: DNA transposons, which move directly by cutting and pasting themselves, and retrotransposons, which replicate themselves into RNA and then back into DNA before inserting into a new location. Their activity can influence the structure and function of genomes over time.