| search quality rater guidelines | Guidelines for human raters that work for Google to determine the quality of real web pages. |
| hits algorithm | Hyperlink-Induced Topic Search is a link analysis algorithm that assesses a value not just based on content and inbound links (authorities), but also its outbound links (hubs). |
| penguin update | a set of Google algorithm updates and data refreshes that help increase the value of its search results. It was announced in 2012 with the aim of decreasing the number of websites that violate Googles Webmaster Guidelines i.e. websites with poor backlink profiles. |
| search history | Search engines track every search users conduct (text and voice), every webpage visited, and every ad clicked on. Search engines may use this data to personalize the results for signed in users. |
| gray hat | A supposed “gray” area between techniques that adhere to Google’s Webmaster Guidelines, but then add an element that bends the rules a little. |
