hyperlink

A hyperlink, or simply a link, is a reference or navigation element in digital documents that enables a reader to move from one resource to another by clicking or tapping. Hyperlinks are a foundational component of hypertext systems, allowing non-linear access to information by connecting related documents, sections within a document, or external resources such as webpages, images, emails, or files.

The concept of hypertext and hyperlinks emerged in the 1960s, with influence from Ted Nelson and the Xanadu project. The term hyperlink is commonly attributed to Nelson, and the World Wide Web later popularized the concept. In the Web, hyperlinks are implemented using markup or related technologies; in HTML, for example, they are created with an anchor element that references a target through a URL via the href attribute. A hyperlink can point to a different document, a specific location within the same document (a fragment), an email address, or multimedia content.

Hyperlinks come in various forms: text links, image links, and button-like links. They can be internal (within the same site) or external (to other sites). When activated, hyperlinks may open in the same window or tab, or in a new one, depending on attributes or user settings. Link appearance changes based on state information such as unvisited, visited, or focused, aiding navigation and accessibility.

Practical considerations include search engine optimization, accessibility, and security. Clear, descriptive link text improves usability and translation quality; links should use secure protocols (HTTPS) and appropriate rel attributes to mitigate certain risks. Properly implemented hyperlinks enhance the interconnected structure of digital information.