The [ ` crossorigin ` ](/en-US/docs/Web/HTML/Element/img#crossorigin)
attribute, in combination with an appropriate [ CORS ](/en-
US/docs/Glossary/CORS) header, allows images defined by the [ ` <img> ` ](/en-
US/docs/Web/HTML/Element/img) element to be loaded from foreign origins and
used in a [ ` <canvas> ` ](/en-US/docs/Web/HTML/Element/canvas) element as if
they were being loaded from the current origin.

[ CORS settings attributes ](/en-US/docs/Web/HTML/Attributes/crossorigin)

    

Some HTML elements that provide support for [ CORS ](/en-
US/docs/Web/HTTP/CORS) , such as [ ` <img> ` ](/en-
US/docs/Web/HTML/Element/img) or [ ` <video> ` ](/en-
US/docs/Web/HTML/Element/video) , have a ` crossorigin ` attribute ( `
crossOrigin ` property), which lets you configure the CORS requests for the
element's fetched data.

[ Preloading content with rel="preload" ](/en-
US/docs/Web/HTML/Attributes/rel/preload)

    

The ` preload ` value of the [ ` <link> ` ](/en-US/docs/Web/HTML/Element/link)
element's [ ` rel ` ](/en-US/docs/Web/HTML/Element/link#rel) attribute allows
you to write declarative fetch requests in your HTML [ ` <head> ` ](/en-
US/docs/Web/HTML/Element/head) , specifying resources that your pages will
need very soon after loading, which you therefore want to start preloading
early in the lifecycle of a page load, before the browser's main rendering
machinery kicks in. This ensures that they are made available earlier and are
less likely to block the page's first render, leading to performance
improvements. This article provides a basic guide to how ` preload ` works.

##  Reference

[ HTML reference ](/en-US/docs/Web/HTML/Reference)

    

HTML consists of **elements** , each of which may be modified by some number
of **attributes** . HTML documents are connected to each other with **links**
.

[ HTML element reference ](/en-US/docs/Web/HTML/Element)

    

Browse a list of all [ HTML ](/en-US/docs/Glossary/HTML) [ elements ](/en-
US/docs/Glossary/Element) .

[ HTML attribute reference ](/en-US/docs/Web/HTML/Attributes)

    

Elements in HTML have **attributes** . These are additional values that
configure the elements or adjust their behavior in various ways.

[ Global attributes ](/en-US/docs/Web/HTML/Global_attributes)

    

Global attributes may be specified on all [ HTML elements ](/en-
US/docs/Web/HTML/Element) , _even those not specified in the standard_ . This
means that any non-standard elements must still permit these attributes, even
though those elements make the document HTML5-noncompliant.

[ Inline-level elements ](/en-US/docs/Glossary/Inline-level_content) and [
block-level elements ](/en-US/docs/Glossary/Block-level_content)

    

HTML elements are usually "inline-level" or "block-level" elements. An inline-
level element occupies only the space bounded by the tags that define it. A
block-level element occupies the entire space of its parent element
(container), thereby creating a "block box".

[ Guide to media types and formats on the web ](/en-US/docs/Web/Media/Formats)

    

The [ ` <audio> ` ](/en-US/docs/Web/HTML/Element/audio) and [ ` <video> `
](/en-US/docs/Web/HTML/Element/video) elements allow you to play audio and
video media natively within your content without the need for external
software support.

[ HTML content categories ](/en-US/docs/Web/HTML/Content_categories)

    

HTML is comprised of several kinds of content, each of which is allowed to be
used in certain contexts and is disallowed in others. Similarly, each context
has a set of other content categories it can contain and elements that can or
can't be used in them. This is a guide to these categories.

[ Quirks mode and standards mode ](/en-
US/docs/Web/HTML/Quirks_Mode_and_Standards_Mode)

    

Historical information on quirks mode and standards mode.

##  Related topics

[ Applying color to HTML elements using CSS ](/en-
US/docs/Web/CSS/CSS_colors/Applying_color)

    

This article covers most of the ways you use CS