A Canonical link element is an HTML element by which a webmaster can prevent duplicate content issues by specifying the canonical or preferred version of a webpage. This is especially helpful when it comes to the organization and ranking of search engines. In regards to Google images in particular, Google has announced support for a canonical link element that can be inserted in the head section of a webpage to help address duplicate issues before they pop up. This element of search engine optimization can help users to narrow down the information that they are looking for and reduce the amount of duplicate images that are presented upon searching.
Duplicate issues generally occur when the same information or image is available on more than one webpage. By using the canonical link element, you can direct users to the preferred content on the subject and help reduce the occurrence of duplicate information. This link helps webmasters to tell search engines that content should be billed as the original and which content is simply a reprint or re-sharing of that original content.
Though it is not insured that the web crawlers or Google’s spiders will follow only these canonical links, it is something that the search engine will honor strongly and stay close to the model unless it may be more beneficial to ignore these links. This element is useful for those webmasters that are looking for original billing when it comes to the content that they are presenting their users on their own sites.