What is the structure that some bacterial cells use to exchange DNA?

Being simple cellular organisms, bacteria usually reproduce through mitosis, or the replication of DNA and associated organelles into two daughter bacterial cells. However, it is also possible for bacteria to share DNA in a process called bacterial conjugation; this allows a cell to share its DNA unique DNA information with another existing cell. To perform this process, bacterial cells use a cellular structure called a pilus, which is a surface strand similar to flagella, but used for this transference instead of for motility. There are many pili on the surface of the cell, and they are constantly breaking off and being reformed. The pili bring the two cells together and allow the transference of DNA information, after which the cells reform their respective membranes and pili, creating two cells with similar genetic information. This allows the consistent transfer of genetic information on an exponential scale, since the two cells can now create four similar cells, which can create eight, and so on.