A

Active Matrix – An advanced LCD technology. Active matrix displays use transistors to directly activate the screen’s diodes, which creates brighter, more vibrant colors.

Analog Signal – A signal in which pixel information is relayed via waves of fluctuating voltage. This is the standard means of transmitting data to a monitor.

Aperture Grille – A set of vertical metal bars that directs the electron beam in a CRT so that it strikes only the phosphors of a desired color.

Aspect Ratio – A comparison between the relative width and height of a computer screen. For example, the standard 4:3 aspect ratio is 4 units wide and 3 units high. The other major aspect ratio found in computer monitors is the 16:9 HDTV standard.

B

Backlight – A light that illuminates foreground images on a flat screen monitor. This helps make images brighter and easier to see in low-light situations.

Bandwidth – The amount of data that can be transmitted in a fixed amount of time. Different measurement schemes include Hertz and Bits Per Second.

Bitmap – An image made up of individual pixels.

Bit – A binary digit. The most basic representation of the binary code (0 or 1) with which the computer works.

BNC (Bayonet Nut Connector) – A high-end coaxial connection that increases signal accuracy from a video source. It features a locking mechanism that helps prevent unwanted disconnections.

Buffer – A temporary data storage area, usually in RAM, that helps keep frequently accessed data available without having to access the hard drive.

Byte – 8 bits. Basically, a unit of measurement that is capable of storing one character.

C

Cathode–Ray Tube (CRT) – The vacuum tube used in most standard monitors and televisions. Inside the tube, an electron beam passes back and forth, illuminating phosphors on the screen. These phosphors make up the image we see.

CCFL (Cold Cathode Fluorescent Lamp) – A type of backlight used in many LCDs.
CD/M2 – The basic measurement of a monitor’s brightness. 1 cd/m2 is equal to the amount of light a single wax candle would give off over one square meter.

CFL (Cold Fluorescent Light) – See CCFL

Component – A video connection scheme that separates the Red, Green, and Blue signals and transmits them across separate cables. The actual connectors on the cables can be either RCA or BNC.

Composite – A video connection method that combine the Red, Green, and Blue signals and carries them on one cable. These usually feature RCA connectors.

Contrast Ratio – The contrast ratio is the comparison between the darkest black and the brightest white that can be shown onscreen. The higher the contrast ratio, the more clear definition there is between light and dark.

D

DDC (Display Data Channel) – A VESA standard that allows the monitor and video card to transmit configuration information between each other.

DDC2B – A newer, bi-directional version of DDC that allows back-and-forth communication between the monitor and video card.

Degauss – The process of eliminating the buildup of stray magnetic fields that alter the electron beam scans. This helps improve image clarity.

Device Drivers – Small programs that tell the computer how to communicate with a particular type of device.

Digital Signal – A signal that uses a stream of binary data (On and Off signals) to transmit the color intensity of a pixel.

Diode – A simple electronic component that allows current to flow through it in one direction.

Dot Pitch – See Pixel Pitch.

DPMS (Display Power Management System) – A VESA standard that prevents screen damage and saves energy by cutting the power to a monitor after a prolonged period of inactivity.

D-Sub – The standard analog cable used to connect a monitor to a video card. Each end features a standard 15-pin connector.

DVI (Digital Video Interface) – A high-bandwidth monitor connection standard that changes an analog signal into a digital one. The three types of DVI connectors are:

DVI-D – Digital connections only

DVI-A – Analog connections only

DVI-I – Both analog and digital connections

E

Energy Star Compliant – A program of the E.P.A. and U.S. Department of Energy that endorses products that are energy efficient.

F

Frequency – The measurement of the amount of waves transmitted in an analog signal over a one-second period, usually expressed in Hertz. The higher the frequency, the faster a monitor’s screen is redrawn and the smoother motion appear.

H

Hz (Hertz) – A measurement of frequency equal to one cycle per second.

I

I/O Port (Input/Output Port) – A bi-directional port that allows data to be transmitted back and forth between devices.

Interface – A means of communicating between two different devices.

Interlaced – An interlaced image is created when the cathode ray fills in even-numbered horizontal lines on one pass, and then odd-numbered lines on the second pass. This process, found mainly in older monitors, can create some onscreen flicker.


K

KB (Kilobyte) – 1,024 bytes. A unit used to describe smaller amounts of memory.

L

LED (Light Emitting Diode) – A type of backlight used in some flat-screen monitors. LEDs warm up and emit light when they are electrically charged. These are generally not as bright as a CCFL.

Light Source – The type of lamp used in an LCD monitor.

Liquid Crystal Display (LCD) – A monitor that uses fluorescent backlights, color filters, and groups of liquid crystals to form the onscreen image. When an electrical signal is sent to the screen, the crystals react by either filtering out or projecting light onscreen.

M

MB (Megabyte) – 1,048,576 bytes. A basic measurement of computer memory.

MS (Millisecond) – One-thousandth of a second. The basic measurement of a hard drive's access speed.

N

Nit – See CD/M2

Non-interlaced – A non-interlaced image is created when the cathode ray fills-in all horizontal lines in one pass. This creates a flicker-free onscreen image. All modern CRT monitors feature non-interlaced displays.

P

Passive Matrix – Passive matrix displays use wire grids to indirectly activate an LCD screen’s diodes. Because of the indirect current, the images aren’t quite as bright as other technologies.

Phosphor – A chemical compound that emits light when excited by electrons. Different formulations produce lights of different colors.

Pixel (Picture Element) – The small cells that visually combine to form images on a screen. Each individual pixel on a monitor is made up of three separate colors (Red, Green, and Blue).

Pixel Pitch – The distance between the center of a phosphor dot of a given color and the center of the next nearest dot of the same color.

Plasma Display – A monitor that uses neon and xenon gas sealed between plates to make up the screen image. Electrodes excite the gasses, causing them to change into UV emitting plasma, which then charges phosphors and creates what the viewer sees. These displays feature thin profiles, large screens, and incredibly vibrant images.

Plug–and–Play (PnP) – A configuration standard that allows a newly installed device to set itself up in the operating system automatically.

Port – The interface in which you connect components to a computer system.

R

RAM (Random Access Memory) – A temporary data storage found in computers and some of their components. It acts as a holding area for data that is waiting to be used.

RCA Connection – A standard connection type found on most video-based consumer electronics.

Resolution – The amount of pixels displayed onscreen vertically times the amount displayed horizontally. The higher the resolution, the more information that can be displayed onscreen. There are a number of standard resolutions, which include:

VGA (Video Graphics Array) – 640 x 480

SVGA (Super VGA) – 800 X 600

XGA (Extended VGA) - 1024 x 768

SXGA (Super XGA) - 1280 x 1024

SXGA+ - 1400 x 1050

UXGA (Ultra XGA) – 1600 x 1200

S

Shadow Mask – A sheet of metal with round holes across its surface, used to direct the electron beam in a CRT. When the beam shines through the holes it only strikes the phosphors of a desired color.

Signal Cable – The type of cable used to connect a monitor to a computer. The two main types are D-Sub and DVI.

Stripe Mask – A metal grille that directs the electron beam in a CRT so that it strikes only the phosphors of a desired color.

S–Video – A video connection method that separates the color information from the luminance. This offers much better image quality than a typical composite signal.

Sync Type – A series of lines that control how an image is placed on a monitor’s screen.

T

TFT (Thin Film Transistor) – A type of active matrix LCD that is very bright and clear but consumes more power.

USB (Universal Serial Bus) – A Plug-and-Play external connection standard used to hook-up many different types of devices. It comes in two flavors:

USB 1.1 – Transfers data up to 1.5 MB per second and supports the simultaneous use of up to 127 devices.

USB 2.0 (Hi-speed USB) – Transfers data up to 60 MB per second and is backwards compatible with USB 1.1.