“The poetry slam was invented by Marc Smith, a construction worker in Chicago in 1984. He was frustrated by snooty, elitist poets who appeared to have no interest in connecting with a live audience, and decided to stage a poetry reading in which the audience would have a way of giving the poets direct feedback – through scores.” http://versesfestival.ca/about-verses/poetry-slam/
The “process” of slam poetry differs from typical poetry. It is often judged by the audience or a set of judges, there are often winners and losers, and the public reading (i.e. the performance) of the poem is important.
One of the “end results” is the same – the creation of a unique piece of art. However, the competitive element of many poetry slams means that winning may be a goal for participants, which is not often the case in poetry.