Event Listeners & Handlers

element.addEventListener('touchstart', handler, { passive: true });
element.addEventListener('touchmove', handler, { passive: true });

To prevent touch events entirely
To improve scrolling performance
Touch events should be passive by default to improve scrolling performance, especially on mobile devices. When a touch event listener is not passive, the browser must wait to see if the handler calls preventDefault() before starting to scroll, causing a delay. Making touch event listeners passive tells the browser it can start scrolling immediately without waiting for JavaScript, significantly improving perceived performance and smoothness.
To enable multi-touch
To prevent event bubbling