URL shortening (a.k.a. URL redirection) is forwarding service allowing anyone to take any existing URL and shorten it.
A uniform resource locator, abbreviated URL (a.k.a. web address), is a specific character string that constitutes a reference to a resource on the World Wide Web. For example, a typical URL would be “http://example.org/home/index.html“. Long URLs present an issue in that they can’t be memorized, or be used in SMS messages and social forums such as Twitter which limits Tweet length to 140 characters.