The <progress> element displays an indicator showing the completion progress of a task, typically displayed as a progress bar.

The <button> HTML element represents a button that triggers some action, such as submitting a form or opening a dialog, styled as a labeled rectangular box by default.

The <object> element represents an external resource such as a PDF or SVG document. It was historically used for plugins such as Shockwave Flash.

The <textarea> element represents an editing control that allows users to enter multi-line, free-form, plain text.

The <iframe> element embeds another HTML page into the current page.

The <img> element adds an image into the document.

The <source> element sets a media resource for the <picture>, <video>, and <audio> elements.

The <track> element is used as a child of the media elements that lets you specify a timed text track to be displayed in parallel with the media element.

The <canvas> HTML element is a space to draw graphics in, using the 2D canvas API, WebGL, or WebGPU.

The WebSocket API opens a two-way communication channel between the user's browser and a server.

The <ol>, <ul>, and <li> HTML elements represent ordered and unordered lists.

The <a> element creates a hyperlink to any resource that's accessible via a URL, such as web pages, files, email addresses, or locations within the same page.

The <area> and <map> elements define a clickable area on an image.

The <div> HTML element is the generic container for content.

The <meta> element represents metadata about the page used by the browser or search engines, including description, keywords, and character sets.

The XMLSerializer API provides the serializeToString() method to construct an XML string representing a DOM tree.

The <menu> element represents an unordered list of action items (<li>), such as a toolbar. It is a semantic alternative to the <ul> element.

The <script> element contains or loads data or executable code. This is typically used to load JavaScript code. The <noscript> element represents alternative content to show when scripting is not allowed.

The <em> HTML element emphasizes or stresses the content, styling text as italic by default.

The <strong> HTML element brings attention to the content, styling text as bold by default.

The <video> element plays videos or movies, optionally with controls provided by the browser.

The <audio> element plays sound such as audio effects or music, optionally with controls provided by the browser.

The <b> HTML element draws reader's attention to text, styling text as bold by default.

A promise represents an asynchronous operation which eventually succeeds or fails.

Typed arrays are ordered lists of JavaScript values, where all values are of the same numerical type, such as 8-bit integers or 32-bit floating point numbers.

Mouse events, such as click, mousedown, or mousemove, fire when users interact with an input or pointing device such as a mouse, trackpad, or touchscreen.

The XMLHttpRequest API makes HTTP requests. It's the predecessor to fetch(). Also known as XHR.

Map objects hold key-value pairs and remember the original insertion order of the keys.

Set objects store unique values of any type.

The :nth-child() and :nth-last-child() CSS functional pseudo-classes match elements based on their index within a list of elements. The :first-child and :last-child pseudo-classes match the first and last element in a list, and the :only-child pseudo-class matches an element with no siblings.