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.

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

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.

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

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

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

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.

Your tweeter reproduces the highest frequencies in a loudspeaker.

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

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.