select element by id:

document.getElementById("bigText");

bigText

select element by name:

document.getElementsByName("radios");

select element by tag name:

document.getElementsByTagName("li");

select element by class name:

document.getElementsByClassName("newClass");

select elements by querySelector:

let elements = document.querySelectorAll(".newClass");
elements.forEach((element) => {
  element.style.backgroundColor = "lightblue";
});
        

DOM traversal

let Lists = document.querySelector(".Lists");
let List1 = document.querySelector("#List1");
Lists.firstElementChild.style.backgroundColor = "lightblue";
Lists.firstElementChild.nextElementSibling.style.backgroundColor = "#FFB3CB";
Lists.lastElementChild.style.backgroundColor = "lightgreen";
List1.children[2].style.color = "red";

let children = Array.from(Lists.children);
children.forEach((child) => {
  child.style.color = "#591D30";
});