Permalink is short for permanent link, which refers to a special resource and makes it permanently available. Permalinks are unique identifiers in the form of URLs that are created with the purpose of always being able to reach the designated content via that URL.
Content on the web is constantly changing. In particular, blogs, wikis, web directories, and news magazines are often changed and updated, which makes access to certain documents, content, and websites difficult. On a news website, a previously published article will be placed towards the back whenever new articles that are more current get added. The same principle applies to blogs. Older posts slide down and won’t be accessible from the homepage anymore. Likewise, in wikis, it is often the case that older versions of the article will no longer be available.
Permalinks are supposed to make such content available that would otherwise not be easily accessible. There are two reasons. First, the content should be provided ideally with the same identifier. Second, the identifiers should be preserved, so that not only users, but also search engines can find and retrieve contents via that identifier.
Web content that would otherwise fade into the background, are therefore provided with a unique identifier. The concept behind it are Uniform Resource Identifiers (URI) which reference a resource by using a unique identification code. In the case of permalinks, these resources are web content which is referenced with a web address in the form of a URL. The URL indicates where specific content on the web is located.
The URL of a webpage that contains various news, may, for example look like this:
However, specific news reports are not accessible via this address. If you want to designate a specific report, you would use a permalink for that specific web content. For example, to reference a single report from 02/20/2014, the Permalink may look like this: www.sample.com/news/newsreport20022014.
This report will then be permanently available under that URL and can be linked by third parties using this permalink.
Ideally, however, a permalink is chosen which describes the resource, such as: www.sample.com/news/facebook-buys-whatsapp
Depending on what content management system is used, very different possibilities exist. A semantic label with appropriate keywords is usually the first choice, but it can be supplemented by a specially generated number codes for large websites.
Permalinks are very important in the field of search engine optimization in order to better identify certain resources and make them permanently available. It is not just about the availability of an article, but also the readability and crawlability for search engines. The URL of a permalink should therefore always consist of important keywords or clear, concise titles with keywords. That way, search engines can put the content in relation to keywords and corresponding indexes and at the same time readers will know at first glance what type of content to expect from the permalink.
Many mistakes can be made with permalinks as well. They should be relatively short. Up to five words is regarded natural by Google. The longer a Permalink is, the less weight it is given in indexing. Some characters such as underscores should be avoided. Words are instead separated by dashes and are usually lowercase. Duplicates of certain words within a URL is also to be avoided. It is particularly important to avoid referencing multiple URL’s in the same resource. This can be interpreted as duplicate content.
All in all, permalinks are about choosing a meaningful unique identifier that describes the resource and makes it permanently available, without violating other criteria of reasonable search engine optimization.