Redirect: A webpage that uses a redirect alerts a browser and search engine that the page's location has changed. This way a user who clicks this link will be taken to the new website's location. This process is sometimes referred to as URL redirection or URL forwarding.
There are two main types of redirects that many websites take advantage of. One is the 301 redirect, which is used for permanent changes; the other, 302 redirects, are for temporary use only. While 301 redirects are the preferred method to use, especially for SEO purposes, 302 redirects should generally be avoided, as search engines often struggle with displaying the correct links for them.
There are also several different ways in which webmasters can redirect URLs. A common method involves adding code to the site's metadata, which helps redirect a page automatically. URL shortening is another form of URL redirection. Domain redirects, which can guide users to the correct website in case of a typo or incorrect domain (.com instead of .org), are also frequently used.
In some cases, a redirect can be used to trick search engines and/or internet users, especially when it comes to more malicious websites. Although a website might display some information in a search engine's results, the redirect tricks it by sending the user to a different location -- which may download malware or other unwanted programs onto the user's computer. This is a common black hat SEO tactic.