Condoms are a form of barrier contraception, that successfully protect against pregnancy and STI’s when used properly. Usually made of thin latex rubber, the sheath is worn on a man’s penis during sex. There are also female versions available but most people opt for the male one because of ease of use and range of choice.Creating a block between the skin and fluids of the penis and vagina, condoms prevent pregnancy by stopping any sperm from reaching an egg. They also ensure that no bodily fluids mix, which is how most STI’s are spread.