An external link is a clickable hyperlink that directs a user to a webpage or website outside of the current domain or website they are browsing. These links are typically indicated by a different color or underlined text, and can provide additional information, resources, or references related to the content on the current page. External links are important for expanding knowledge and connecting users to a wider network of information on the internet. They can also be used for citation purposes, allowing readers to easily access the original source of information. However, it is important to exercise caution when clicking on external links, as they may lead to unreliable or malicious websites.