Short answers, pulled from the story.
Toots Hibbert of Toots and the Maytals named the genre. The word reggae first appeared in print with the 1968 single "Do the Reggay" by the Maytals, which Hibbert said came from an improvised moment during a morning session with two friends.
Reggae developed from ska and rocksteady, both of which originated in 1960s Jamaica. Ska emerged in the late 1950s from a mix of American R&B, doo-wop, and mento, a rural Jamaican folk form. Rocksteady arose in the mid-1960s as a slower, more romantic evolution of ska.
Reggae accents the second and fourth beats rather than beat one, with staccato guitar or piano chords on the offbeats (called the skank) and the drum emphasizing beat three. The bass guitar carries a thick, heavy tone with reduced high frequencies, and it often functions as a percussion instrument as well as a melodic one.
Rastafari, an Afrocentric religion that emerged in Jamaica in the 1930s promoting pan-Africanism, deeply shaped reggae's lyrics, imagery, and spiritual tone. From the 1970s onward, reggae spread Rastafarian beliefs internationally, and musicians were widely regarded as cultural messengers. Rasta drummers like Count Ossie participated in some of the genre's earliest important recordings.
Reggae-influenced tracks reached the top of the U.S. Billboard Hot 100 in late 1972. Three Dog Night hit number one in September with a cover of the Maytones' version of "Black and White", and Johnny Nash held the top spot for four weeks in November with "I Can See Clearly Now".
UNESCO added "reggae music of Jamaica" to its Representative List of the Intangible Cultural Heritage of Humanity in November 2018, citing the genre's contribution to international discourse on injustice, resistance, love, and humanity.