What is a vasectomy?

A Vasectomy is when the tubes, the Vas Deferens, that deliver sperm from a man’s testes to his Prostate are cut and tied in a knot near the top of the man’s scrotum.
The purpose of which is to stop sperm from being ejaculated, so the male’s semen is sterile.

To add: Depending on the doctor they can also be cauterized to help assure a successful operation. It sounds terrible but I went though it after my 3rd child and it is really not that bad. During the process they cut a small slit in the scrotum and pull the tubes out and cut, cauterize and tie them. From a “laying on the table” viewpoint there is a little pressure and a “pinch” and thats really about all that you feel. Expect to be sore for about a week.