The Document Object Model (DOM) is a programming interface for web documents. It represents the structure of a document (like an HTML or XML file) as a tree of objects, allowing developers to access and manipulate the content, structure, and style of a webpage.

You can select an element from the DOM using methods such as `getElementById()`, `getElementsByClassName()`, `querySelector()`, or `querySelectorAll()`.

Event delegation allows you to add a single event listener to a parent element instead of adding multiple listeners to each child element. This is useful for handling events efficiently and when elements are dynamically added or removed.

You can manipulate an element's attributes using `setAttribute()`, `getAttribute()`, or `removeAttribute()`. To manipulate styles, you can modify the element's `style` property directly in JavaScript.