AAC
A standardized, lossy compression and encoding scheme for digital audio. AAC is considered the successor to the MP3 format by MP3's creator, Fraunhofer IIS. AAC's most famous usage is as the default audio format of Apple's iPhone, iPod, iTunes, and the format used for all iTunes Store audio (with extensions for proprietary Digital Rights Management (DRM) where used). AAC is also the standard audio format for Sony's PlayStation 3, the MPEG-4 video standard, and several digital radio initiatives.

Access Point
The wi-fi receiver that communicates with your wi-fi adapter to allow you access to the Internet. At home, you might attach an access point to your cable or DSL modem. At a hotel or coffee shop, the access point is normally located in the ceiling, out of sight.

ActiveX
With ActiveX, Web sites can be animated using multimedia effects, interactive objects, and sophisticated applications that create a user experience comparable to a high-quality CD-ROM. The same effects can be experienced with Java, Shockwave, Flash, and numerous other applets and programs-the difference is that ActiveX is an exclusive Microsoft product making use of ActiveX Controls.

AirPort
Apple's name for wi-fi. No need to worry, the PowerBook you want will work with the 802.11b wi-fi network at your local Starbucks.

AMR-WB
Short for Adaptive Multi Rate -- WideBand AMR-WB is a standard speech codec that uses a wider bandwidth of 50 to 7000 Hz to offer a higher speech quality. AMR-WB is the ITU-T G.722.2 specification and is standardized for used in networks such as UMTS.

AOL Mobile Communicator
Similar to Blackberry, it lets AOL users send and receive e-mail and instant messages over a public, two-way wireless network via a small handheld device.

Audio
Of or relating to audible sound, that which you hear (as opposed to video). The sound humans hear, BTW, is normally in the 15,000 to 20,000 Hz range.

AVI
A Windows audio/video (multimedia) file, it is a common format you will find on the Internet for developing and viewing small movies and videos. These files are usually pretty large and would require a connection of 28.8 or better to download in any kind of reasonable time. A 20 second movie clip in AVI format could be as large as 3MB and could take about 15 minutes to download to your computer. Other types of video files found online include MOV, MPEG, and ASF.