The return value determines if you consumed the touch event.

In other words true means that this touch event is interesting to you and all follow up calls of this touch event like ACTION_MOVE or ACTION_UP will be delivered to you.

If you return false than the touch event will be passed to the next View further up in the view hierarchy and you will receive no follow up calls. The touch event will continue to be passed further up the view hierarchy until someone consumes it.