In recent years there was (and still is) a dramatic decrease in sales figures of traditional PCs like desktops and laptops, at least in the consumer market.
So mobile devices seem to be the future for end users.
With the ongoing trend to use web technologies for mobile devices, there is a need to optimize the user experience for touch input.
The HTML5 Touch Events specification has finally reached the W3C recommendation state, so now it is an official web standard.
The spec defines four different events which are quite self-explanatory:
Regarding browser support, Firefox, Chrome, and the browsers of iOS and Android support the touch events spec (even quite old versions of these mobile operating systems).
As of today, Internet Explorer has no relevance for mobile devices, so you can safely ignore the fact that IE doesn’t support the spec.