| ahrefs | Founded in 2011 by Dmitry Gerasimenko, Ahrefs is an SaaS SEO platform most popular for its backlink discovery tool Site Explorer. |
| pop-under | Form of advertising that creates a separate browser window, but places it under the active one so as not to be disruptive. |
| cgi | Common Gateway Interface (.cgi) agreement between HTTP server implementers about how to integrate gateway scripts and programs |
| source/medium | A section of Google Analytics that combines Traffic Source and Traffic Mediums. Source: the origin of traffic to a website. Examples might include Linkedin, Bing, Google, Facebook, etc. Medium: the general category of the source, for example, cost-per-click paid search (CPC), web referral (referral), and organic search (organic). |
| algorithmic penalty | The sanctioning of a website by one of the algorithm updates released by Google. |
