A misnomer (term applied improperly) which includes all acts of oral stimulation on the male's penis.
The original and true meaning of blowjob: the act of a woman licking a man's penis, liberally applying saliva to the length (especially the head), and then exhaling (blowing) a cool stream of air onto the penis, thus giving the man pleasure. Most often, adding in direct concentration on the head itself, the man can be brought to a very satisfying climax.
(It's up to the female involved if she wants to have her man ejaculate on her breasts/stomach, or to swallow the load/spit it out; yet, it's worth noting that most men will want her to swallow and her doing so will cause the man involved to crave her even more. Spitting is highly frowned upon, as it signals a form of rejection to the male.)
Not to be confused with:
Headjob - sucking on the head of the penis to stimulate the man toward orgasm
Deepthroating - inserting the penis into one's mouth, usually to the point of invoking the "gag reflex"; many times, a man will want to ejaculate as deeply into a woman's mouth as possible, as to encourage swallowing. With practice, any woman can learn to get past the usual "gag reflex" reaction, and deeply satisfy her man.
Jill licked the length of Jack's penis, giving it a thick covering of saliva. Then, she proceeded to blow a cool stream of air over it, giving her man an ultra cool sensation over his penis. He enjoyed the wonderful art of the blowjob with a smile. Afterward, Jill concentrated on the head of Jack's penis, giving him a wonderful headjob; and, she proceeded to deepthroat Jack and allow him to ejaculate in her mouth, eagerly swallowing her man's semen.