A ranking penalty applied by a human reviewer at Google after identifying a violation of their webmaster guidelines. Manual actions typically target unnatural backlink patterns, thin content, or cloaking, and must be resolved through a reconsideration request.
A brief HTML attribute summarizing a page's content that often appears as the snippet beneath the title in search results. While not a direct ranking factor, a compelling meta description increases click-through rate, which indirectly benefits SEO.
An HTML meta tag once used to declare a page's target search terms. Google has ignored meta keywords for ranking purposes since 2009, though a few minor search engines still consider them.
An HTML meta refresh tag that automatically forwards visitors to a different URL after a set number of seconds. Server-side 301 redirects are preferred because they pass link equity more reliably and don't create a delay for users.
An HTML directive that tells search engine crawlers whether to index a page and whether to follow its links. Common values like "noindex, nofollow" give you page-level control over what appears in search results.
An exact replica of a website hosted on a separate server or domain, typically used for load balancing or geographic redundancy. Without canonical tags pointing to the original, mirror sites create massive duplicate content problems.