The template Template:Link is a helper to get information about links on pages. It's purpose is:
- simplifiying the usage of links
- unifying the usage of links
- keeping track of link information in a semantic way
By using the Template:Link you can query about the usage of Links being placed on page in this fassion. One usecase is the Template:WhatLinksHere template. It allows to query for the pages that link to the current page.