A condom is a barrier device used during sexual intercourse to prevent an unwanted pregnancy . It is the simplest device used for contraception . It is put on the man’s erect organ and physically blocks the ejaculated semen from entering the female genital tract . Condoms are water proof and elastic , inexpensive and easy to use . They are also used with variety of other contraceptive methods .
They not only prevent pregnancy but also give certain medical advantages to their users .
They protect against sexually transmitted diseases which include gonorrhea and syphilis . And one of their main advantage is protection from transmission of HIV ( AIDS ) .
They are used to collect semen sample in artificial reproductive techniques where male sample is collected through masturbation for artificial insemination or invitro fertilization .
They are used to cover the endovaginal probe of ultrasound . 
Condoms have some strange non medical uses and in history they have been used for lots of other purposes .
They are used to keep oil samples .
They have been used in the smuggling of various drugs like cocaine and heroine .
They are used to protect the microphones during underground recording .
They are used to keep the candles dry during camping .
