| tfidf | (Term frequency-inverse document frequency) A measurement used by Google to determine how important a keyword is on a webpage by comparing its frequency and usage on other webpages. |
| blog comment spam | comments that are left on a blog that add no value to the article or discussion, typically including a backlink to an external website. Blog comment spam may be automated by a bot or left manually. |
| pogo-sticking | When, after entering a query, a searcher bounces back and forth between a SERP and the pages listed in those search results. |
| pay-per-click | or PPC: Online advertising approach that determines the cost of an ad by the number of people who click on the ad. |
| disavow links | Disavowing links is the process of telling Google that you do not want the links to count towards your site. For example if you feel that the links are spammy, or that they had been purchased as part of a previous SEO campaign and you need to now tidy them up. You can disavow links via the Disavow tool in Search Console. |