Salsa was the outcome of the movie Dirty Dancing though it wasn’t called Salsa in the film.  Salsa means “spicy” and so we have spicy dancing based on an older latin dance called Mambo. Salsa is a “today” take on this dance because it is the version danced by the “street dancers” or true “social dancers”. 
As the Puerto Ricans and Cubans found their way to North America, especially in the Florida and New York State areas, they brought with them their built in sense of balance and rhythm. Matching this with the fabulous authentic latin music played in the clubs turned everyone’s eyes to admire this genetic trait. Wanting to emulate that physical rhythm has created a huge Salsa wave everywhere.  Adding rhythms such as Batucada has helped sustain the Salsa popularity.
There are only a few original latin American dances.  This would include Rumba, Son, Samba, Merengue, Cha Cha, and Mambo.  The Music and Movie industry have caused the rise of other dances which attach themselves to the exciting Latin flavour.