There are three, (some say more), waves of ska music.
1st Wave – Original ska from Jamaica in 1950s and 60s. A fusion of US jazz and R&B with Caribbean musical styles like mento and calypso. A forerunner to Rocksteady and reggae if featured artists like The Skatalites, Prince Buster, Desmond Dekker and early Bob Marley.
2nd Wave – Originated in Coventry, UK. Late 1970s to early 80s. It was a British ska revival and was a fusion of original 1st wave ska with punk (harder edged rock sound of the day) and was dubbed 2 Tone. It featured bands like The Selector, The Specials, Madness, Bad Manners, The Beat.
3rd Wave – From the US. 1990s onwards. Far less of the 1st wave ska and more of a guitar led sound. Bands like No doubt, The Mighty Mighty BossTones, Bim Skala Bim, The Toasters, The Uptones, Reel Big Fish.
Videos to watch:
3 Generations Of Ska - (short)
https://youtu.be/uzHszWJomxw?si=Iw0tts_JZZchamvC
The Complete History Of Ska Music: From Jamaica To New England (from a US point of view) - (longer)
https://youtu.be/vEnTr3riXSw?si=Asp5yGxJ2X8yPCfE