2. Algorithm. A set of rules that a search engine uses to rank
the pages contained within its index in response to a
particular query. No search engine reveals exactly how its
algorithm works, to protect itself both from competitors
and from those who wish to spam the search engine.
3. Back links. These are links to a website from external
sources, including other web pages, directories, and
advertising.
4.
5. Click-through rate. How many people clicked on a link, as a
percentage of the total number of people that saw the
link.
6. Cloaking. The act of serving content to search engine
spiders that is different to what normal visitors would see.
Search engines will ban you if they find you doing this.
7. Contextual links. Contextual links are displayed on web
pages when the content on the page indicates to an ad
server that the page is a good match for specific keywords
or phrases.
9. Cost per click (CPC). A system where an advertiser pays an
agreed amount for each click someone makes on a link
leading to their website.
10.
11.
12.
13. Directories. A type of search engine where listings are
gathered by humans, rather than by automated web
crawlers.
14.
15. Graphical inventory. Banners and other ads that appear
depending on the keywords a page contains. This includes
pop-ups, browser toolbars and rich media.
21. Meta-search engine. A search engine that returns listings
from two or more other search engines, instead of using
its own index.
22.
23. Meta description tag. This meta tag allows pages to
provide descriptions to search engines.
24. Meta keywords tag. Allows authors to add text to a page
to help with the search engine ranking process.
25. Meta robots tag. Allows page authors to keep some web
pages from being indexed by search engines. Similar to a
robots.txt file.
26. Natural listings. The listings that search engines do not
sell. Instead, sites appear solely because a search engine
believes it is important for them to be included, regardless
of payment. Note that paid inclusion listings are still
treated as natural listings by many search engines.
28. Paid inclusion. An advertising program where pages are
guaranteed to be spidered and included in a search
engine's index in exchange for payment.
29.
30. Paid listings. Listings that search engines sell to
advertisers, usually through paid placement or paid
inclusion programs.
31. Pay-for-performance. A term popularized by some search
engines as a synonym for pay-per-click. It stresses to
advertisers that they are only paying for ads that
"perform" in terms of delivering traffic, as opposed to
CPM-based ads, where ads cost money even if no-one
clicks on them.
32. Paid placement. An advertising program where listings
appear in response to particular search terms, with higher
rankings typically obtained by paying more than other
advertisers.
33. Rank. The order in which web pages are listed in search
engine results.
34.
35. Results page. The page that appears after a user enters
their search terms.
36. Robots.txt. A file used to keep web pages from being
indexed by search engines.
37. Search engine. A service designed to allow users to search
the web, or another database of information.