DOM

The JavaScript HTML DOM (Document Object Model) is a powerful tool that represents the structure of an HTML document as a tree of objects. It allows JavaScript to interact with the structure and content of a webpage. By manipulating the DOM, you can update the content, structure, and styling of a page without requiring a page reload.

Why is DOM Required?
Dynamic Content Updates: Without reloading the page, the DOM allows content updates (e.g., form validation, AJAX responses).
User Interaction: It makes your webpage interactive (e.g., responding to button clicks, form submissions).
Flexibility: Developers can add, modify, or remove elements and styles in real-time.
Cross-Platform Compatibility: It provides a standard way for scripts to interact with web documents, ensuring browser compatibility.

Undefined :
A variable that is declared but not initialized will have the value undefined.
let x; // variable declared but not initialized
console.log(x); // Output: undefined
Null :
Null is basically an assignment value given to a variable. The variable which has been assigned as null contains no value.
let noValue = null