Accessibility
The practice of making websites usable by disabled people - especially blind people.

AdSense
A service offered by Google to monetize your website by delivering content specific ads.

AdWords
Google CPC (Cost Per Click) based text advertising.

Affiliate Program
Member based sales where an authorized affiliate is paid a percentage of revenue for helping promote products and services.

AOL
America On-Line - a popular ISP network for novice users; uses Google as part of its search results.

API
Stands for Application Program Interface. An API is a set of routines, protocols and tools for building software applications; and it determines how a service is invoked through the application.

AskJeeves
Considered by some to be one of the Top 3 engines along with Yahoo and MSN, following Google.

AlltheWeb
Second Tier search engine.

AltaVista
Used to be the #1 search engine until Google came along.

Algorithm
A mathematical formula used to determine the value of a page when compared against others.

ATF, or Above the Fold
The part of the users screen that is always displayed - without scrolling further down.

Anchor Text
Also known as Link Text, the clickable text of a hyperlink.

ALT Text
The text that appears when you mouseover an image or a picture.

Authority Site
A site that has many In-Bound links coming to it, and very little outbound links.

AIDA
Attention, Interest, Desire, Action: A term used to describe a formula to increase conversions.