Sexual intercourse, or coitus or copulation, is principally the insertion and thrusting of a male's penis, usually when erect, into a female's vagina for the purposes of sexual pleasure or reproduction. This is also known as vaginal intercourse or vaginal sex. Other forms of penetrative sexual intercourse include penetration of the anus by the penis, penetration of the mouth by the penis or oral penetration of the female genitalia, sexual penetration by the fingers, and penetration by use of a strap-on dildo. These activities involve physical intimacy between two or more individuals and are usually used among humans solely for physical or emotional pleasure and commonly contribute to human bonding. A variety of views concern what constitutes sexual intercourse or other sexual activity, which can also impact views on sexual health. Although the term sexual intercourse, particularly the variant coitus, generally denotes penile-vaginal penetration and the possibility of creating offspring, it also commonly denotes penetrative oral sex and particularly penile-anal sex.