URL shortening is a technique on the World Wide Web in which a Uniform Resource Locator (URL) may be made substantially shorter and still direct to the required page. This is achieved by using a redirect which links to the web page that has a long URL. For example, the URL "http://example.com/assets/category_B/subcategory_C/Foo/" can be shortened to "https://example.com/Foo", and the URL "http://example.com/about/index.html" can be shortened to "https://my-link.in/593aed0c74663". Often the redirect domain name is shorter than the original one. A friendly URL may be desired for messaging technologies that limit the number of characters in a message (for example SMS), for reducing the amount of typing required if the reader is copying a URL from a print source, for making it easier for a person to remember, or for the intention of a permalink. In November 2009, the shortened links of the URL shortening service Bitly were accessed 2.1 billion times.
Short your favourite link and make it beautiful, the long links are so difficult to remember so, converting long link to short one is good practise to do any thing with it, remember, share and ect.
Of course you can share the link with your friends, using any social network, just copy the shorted link, then do what you need with it.
You can short your link with password, so no body can know what the link is. this way is good for encrypt the real content of some link, only who has the password is able to see the real content.