Duplicate content

Duplicate content – duplication of content published on websites, which may occur within one or multiple domains. Identical content then is available under several web addresses. Duplicate content within a single domain can occur when the homepage or subpages are accessed from several addresses, such as: http://XYZ.com, http://www.XYZ.com, http://XYZ.com/index.html (for the homepage) or http://XYZ.com/category, http://XYZ.com/category/index.html (for subpages). The reason for duplicate content can also be the simultaneous running of the site for standard devices (e.g., desktop computers) and mobile devices, the lack of use of canonical addresses and 301 redirects, and a CMS that displays the same article on the home page and in another tab. When content is copied from one site and published on other sites, we are dealing with duplicate content across multiple domains. This can be the result of text theft or failure to mark the source with a link (e.g., when publishing on external sites). Duplicate content is just as often seen in the case of online stores, where descriptions from manufacturers are not changed.