What is the difference between event.stopPropagation() and event.preventDefault()?

• stopPropagation() — stops event from bubbling to parent elements
• preventDefault() — cancels browser default (link navigation, form submit) but still bubbles
• stopImmediatePropagation() — stops bubbling + prevents other listeners on same element

link.addEventListener('click', (e) => {
  e.preventDefault();    // don't navigate
  e.stopPropagation();   // don't bubble up
  doSomething();
});