The checksum of a file is a sequence of figures and letters defining precisely (but not unique) a file to know if it was corrupted. Google also uses a checksum algorithm to encode exchanges of data between her toolbar and his servers.

Technique aiming at ameliorating the positioning of a page within research motors by providing in these last a version different from that visible by the internauts. This practice, considered as of the spamdexing, can be source of black-list.

Tools returning various information about URL. Form "control: www.exemple.com ", they are directly grabbed in research fields Google (without inverted commas). List of most employed Google Controls:
- Link returns the list of the backlinks of grabbed URL.
- Site returns the list of the pages of the grabbed site (work only with grabbed name of domain. Eg: www.exemple.com) indexed by Google.
- Information returns the information of grabbed URL if this last is indexed by Google.
- Related returns the list of the pages that, according to Google, the topic is close of grabbed URL.

Number of pages classified by research motors for one (couple of) keywords(s). Coupled with a qualitative analysis of pages put in first position of the results of research motors on your requests, it determines the feasibility of a positioning: the more competition is big and the more PageRank ™ of the "leader" is well brought up, the more positioning is difficult. Every motor displays the competition linked to grabbed request, at the head of its pages of results. Each of them has his own way to index Web pages; the competition for the same request is variable from a motor to the other one.

(Combination of) grabbed term (s) by the internauts representative of the contents waited by these last in results shown by research motors.

See "Advertising Positioning".

See « Robot (of indexation) ».