acronyms. With all that information, it's a challenge to cut through the clutter and get exactly what you need.

To make it easier, we're offering this glossary of common terms, with descriptions and explanations in plain English.

This recording format surrounds the viewer with audio from six separate speakers—particular sounds will often come from a specific location to enhance the listening experience. The setup includes three speakers (right, left and center) in front of the viewer, right and left speakers behind, and a sixth speaker for low-frequency sounds. While 5.1 is the most common option, 6.1- and 7.1-channel systems are also available, usually adding speakers at side locations.

A popular alternative to 5.1-channel surround sound for smaller rooms where space is limited. This setup includes two front speakers and a third speaker for low-frequency effects. By using digital signal processing technologies, 2.1-channel sound can deliver much of the performance of a surround-sound speaker system.

Commonly used in home theater receivers and amplifiers, DSP adds various sound effects, such as reverberation and echo, to enhance the audio experience.

The ".1" of 5.1 channel sound, LFE is the audio portion of a movie soundtrack designated to the lowest frequencies. These are sounds many people say they "feel"—rumbling vehicles, explosions and other dramatic movie sounds.

MP3 is the standard for digital audio encoding used for listening to music on most portable digital audio players. Engineers from several different companies developed the format, which was approved as an industry standard in 1991. Apple® iTunes® uses its own proprietary digital media player application for digital music and movies.

These are numbers that, in simplest terms, refer to the resolution of an HDTV screen. The number "1080" refers to 1,080 lines of vertical resolution (1080 horizontal scan lines). The letter "p" represents progressive scan, the way in which the image is refreshed; an alternate is "i," representing "interlaced." 1080p currently provides the most detail, as in Blu-ray Disc™. 720p resolution has a lower resolution than 1080p, but the difference in picture quality can be virtually indiscernible, especially when seated at the proper distance from the screen, and with smaller TVs—less than 40 inches diagonal measurement.

The new industry-standard format for high-definition discs. Blu-ray Disc has clearer, more detailed images than conventional DVDs, and can store more than five times the amount of video and audio information, which is needed for a high-definition version of a movie. Additional benefits include multi-channel sound, and the ability to create playlists, edit or reorder programs—even download entertainment features.

This digital television broadcasting system has higher resolution than the previous broadcast standard, and is not available on older-format systems. HDTV signals use video compression to carry more information and require less bandwidth. It also has the highest standards of all digital signals. The two most popular HDTV playback technologies are:

This technology enables an advanced DVD player to play conventional DVDs and to utilize a higher resolution on an HDTV screen by upconverting (or upscaling) a lower-resolution signal, such as 480p, to a higher-resolution signal up to 1080p. Although picture quality, apparent detail and color are improved, an upconverted DVD is not a true HDTV experience, because the source content is limited by the information on the DVD.

This compact interface delivers high-definition video and multi-channel audio to your digital TV or home theater audio system in just one connection. All-digital and uncompressed, HDMI provides the highest-quality video, up to 1080p. The interface technology is also designed to support future enhancements in audio and video devices.

The high-def digital video input connection found on many flat-panel TVs, DVI is now being replaced with the more advanced HDMI connector, which combines audio and video in one cable.

The best quality analog video connection available. It splits the signal into three color components: Luminance, Blue color difference and Red color difference. The European SCART connector splits the signal into red, green and blue color components.

S-video splits the signal into two components and provides significantly higher resolution than composite video, but not as high as component.

Composite video is a basic single-wire video connection that utilizes an RCA cable for home entertainment systems.

Bose® Direct/Reflecting speaker technology produces at-home sound similar to a concert hall experience. Sound is reflected off walls and other flat surfaces to deliver clear, lifelike stereo performance everywhere in the room.

This proprietary Bose technology uses precisely tuned tubes (or waveguides) to amplify the output from speakers for lifelike sound from a small enclosure. For example, the Bose Acoustic Wave® music system, which is less than a foot high, contains a folded waveguide nearly seven feet long.

The ADAPTiQ® audio calibration system provides home theater performance customized to the shape, size and furnishings of the listening area. It analyzes the way your room's dimensions and other variables affect sound, then automatically adjusts the sound to the acoustics of your room.

The uMusic intelligent playback system, found in select Bose home entertainment systems, customizes your CD music collection. It digitally stores thousands of songs, and groups selections to your preferences. As you keep listening, it rates, refines and updates your selections to provide a variety of personalized listening experiences.

Bose proprietary active noise-reduction technology monitors and cancels unwanted sounds before they reach your ears. So you hear more of your music and movies, with fewer distractions.