Terminology

4K:
4K, also known as Ultra HD, refers to a resolution of 3,840 x 2,160 pixels, which is four times as many pixels than Full-HD. 4K has a total of about 8.3 million pixels.

Aspect Ratio:
The aspect ratio of an image is the relationship of the width to the height. It is the “shape” of the video. Standard definition video has a 4:3 aspect ratio which met the requirements of pre-HD televisions. Modern HD shows are 16:9 (also known as widescreen). This means that the ratio of the width to the height of the image is represented by the ratio 16:9. This can also be reduced and written out as 1.78:1. Many motion pictures use a different aspect ratio for an even more expansive effect, including 1.85:1 and 2.35:1. When the aspect ratio of a film doesn’t match the aspect ratio of a display device like a television, the device will show black boxes (letterboxes) to make up the additional space.

Contrast Ratio:
Contrast Ratio is the ratio between the brightest white that a screen can produce and the darkest black. In more general terms, contrast is the difference between light and dark values in a picture. A good contrast is one with many steps between the blackest blacks and the brightest whites.

Decibel (dB):
The decibel is a unit of measurement that describes loudness.

Frequency:
The specific range or band for a given sound or tone. High frequency sounds are handled by tweeters and low frequency sounds are handled by more conventional drivers and woofers.

Full-HD:
Full-HD refers to the pixel resolution of a screen or projector. In the case of Full-HD, the resolution is 1980×1080 pixels.

Driver:
This is the part of the speaker that moves and makes the noise. Larger drivers can typically handle reproduction of lower frequencies while smaller drivers can reproduce higher frequencies.

HDMI:
Provides digital audio and video over a single cable from source components to Projectors and televisions.

Lumens:
Lumens are the measurement of brightness that a projector gives out.

Passive:
A passive speaker requires amplification from a receiver or an amplifier.

Receiver:
A receiver, or AV receiver, serves as a switcher and processor for audio and video devices. It will also contain amplifiers to power the speakers connected to it.

Tweeter:
Your tweeter reproduces the highest frequencies in a loudspeaker.

Watt:
The watt is a unit of power. The more watts, the more power but can be affected by other factors.

Zone:
In your home, a zone is a particular area in a home, such as a theatre room, a kitchen, a bedroom, or outdoor patio. A multi-zone AV receiver means that it has amplifier channels and/or outputs that can deliver audio to more than one room.