The TouchEvent interface represents an event sent when the state of contacts with a touch-sensitive surface changes. This surface can be a touch screen or trackpad, for example. The event can describe one or more points of contact with the screen and includes support for detecting movement, addition and removal of contact points, and so forth.
A TouchList listing all the Touch objects for touch points that are still in contact with the touch surface and whose touchstart event occurred inside the same target element as the current target element.
A TouchList listing all the Touch objects for touch points that are currently in contact with the touch surface, regardless of whether or not they've changed or what their target element was at touchstart time.
The TouchList interface represents a list of contact points with a touch surface; for example, if the user has three fingers on the touch surface (such as a screen or trackpad), the corresponding TouchList object would have one Touch object for each finger, for a total of three entries.