Question 210 - Certified B2B Commerce Administrator discussion

The Shadow DOM is a standard that provides encapsulation for the internal document object model (DOM) structure of a web component. The DOM is the representation of the HTML elements and attributes of a web page in a tree-like structure. The Shadow DOM allows creating a separate DOM tree for each web component, which is hidden from the main DOM tree.This means that the markup, style, and behavior of the web component are isolated from the rest of the page1. The purposes of the Shadow DOM in a Lightning web component are:

It encapsulates the internal document object model (DOM) structure of a web component. This means that the web component has its own scope and namespace, and does not interfere with other elements on the page.For example, the web component can use its own CSS selectors and variables without affecting or being affected by the global CSS2.The web component can also use custom HTML tags without conflicting with existing or future HTML standards3.

It allows components to be shared while protecting them from being manipulated by arbitrary code. This means that the web component can be reused in different contexts and applications, without worrying about external code changing its functionality or appearance.For example, the web component can be embedded in another web page or application, and it will still work as intended, regardless of the surrounding code4.The web component can also prevent malicious code from accessing or modifying its internal state or data5.