Traversing means "move through", are used to "find" (or select) HTML elements based on their relation to other elements. Start with one selection and move through that selection until you reach the elements you desire.
By using
Closest
const closestElement = targetElement.closest(selector);
Siblings
const previous = element.previousSibling;
const next = element.nextSibling;
Children
const container = document.querySelector('#container');
const children = container.childNodes;
Parent
const current = document.querySelector('#main');
const parent = current.parentNode;