Final answer:
An alternate page with a proper canonical tag is a technique used in SEO to designate the preferred version of a page when multiple versions exist, helping to prevent duplicate content issues and maintain search engine rankings.
Step-by-step explanation:
An alternate page with a proper canonical tag is a technique used in Search Engine Optimization (SEO) to prevent duplicate content issues. When a website has multiple versions of the same page, such as a desktop version and a mobile version, a canonical tag is added to indicate the preferred version. The canonical tag helps search engines understand which version of the page should be considered the original or primary version. This helps consolidate the PageRank and prevents any negative impact on search engine rankings.
For example, let's say you have a website with both a www and non-www version, as well as both a http and https version. To avoid duplicate content penalties, you can designate one version as the canonical version by adding a canonical tag to the alternate versions. The canonical tag would point to the preferred version, telling search engines that it should be indexed and considered the primary version.
In summary, an alternate page with proper canonical tag is a way to designate the preferred version of a page when multiple versions exist, helping to prevent duplicate content issues and maintain search engine rankings.