Contains language specific links.
Public specification of a preferred URL for a page allows search engines to understand the original location for content.
The OpenSearch description document format can be used to describe a search engine so that it can be used by search client applications.
[url] uses conditional comments that are supported by Microsoft Internet Explorer. They allow web developers to show or hide HTML code based on the version of the viewer's browser.
The DOCTYPE is a required preamble for HTML5 websites.
Adapting images for high-resolution and low-resolution displays.
A way to make Web content and Web applications more accessible to people with disabilities. It especially helps with dynamic content and advanced user interface controls developed with Ajax, HTML, JavaScript, and related technologies.
The page shows content with an iframe; an embedded frame that loads another webpage.
The defer attribute gives a hint to the browser that the script does not create any content so the browser can optionally defer interpreting the script. This can improve performance by delaying execution of scripts until after the body content is parsed and rendered.
JavaScript is a scripting language most often used for client-side web development.
Cascading Style Sheets (CSS) is a stylesheet language used to describe the presentation of a document written in a markup language. Its most common application is to style web pages written in HTML
The description attribute provides a concise explanation of the page content.