Glossary of cable and connectivity terms

 

0-9   A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z

 

 

0-9       (back to top)

 

10-Base2 – Short for 10 Megabit, baseband, 200 Meters. Refers to an older Ethernet standard that used RG-58 Thinnet coaxial to network computers in a daisy-chain topology. This system is antiquated.

 

10-BaseT – Short for 10 Megabit, baseband, Twisted pair. An upgrade to Ethernet from 10-Base2, it switched from the coaxial daisy-chain method to using a star topology running over twisted pair cable. This allowed for greater flexibility and reliability. Still used today, although the speeds have increased. See 100-BaseT and Gigabit.

 

100-BaseFX – Short for 100 Megabit, baseband, Fiber cross-connect. See 100-BaseT. Basically, Ethernet over fiber optic instead of twisted pair.

 

100-BaseT – Short for 100 Megabit, baseband, Twisted pair. See 10-BaseT. An upgrade that increased the speed from 10 Megabits per second (Mbps) to 100 Mbps. See also Gigabit.

 

16:9 – Widescreen aspect ratio used for a video display. The display measured is 16 units wide for every 9 units tall. This creates a rectangular viewing area that better represents a movie theater screen.

 

4:3 – Standard aspect ratio used for a video display. The display measured is 4 units wide for every 3 units tall. This creates an almost square viewing area. Standard TV’s and computer monitors use a 4:3 aspect ratio.

 

5.1 – A type of surround sound with 5 distinct sound channels and a LFE (low-frequency effects) channel; Center, Front Left, Front Right, Rear Left, and Rear Right. The .1 refers to the LFE channel, which is so named because it only reproduces the lower 1/10 of the sound frequency (the deep bass tones) of the other channels. Each channel requires a separate speaker. Dolby and DTS both offer 5.1 Surround technologies.

 

6.1 – The same as 5.1, with the addition of a Rear Center channel.

 

7.1 – The same as 5.1, with the addition of a Left Rear Center channel, and a Right Rear Center Channel. In a 7.1 setup, the Rear Left and Rear Right of the 5.1 setup are pushed a bit forward to create a more rounded shape to the sound field.

 

A         (back to top)

 

AC –Alternating Current. An electric current that reverses its direction at regularly recurring intervals. Common household electrical circuits are AC. 

 

Active – used to describe a device or circuit that requires power to operate. Opposite of Passive.

 

ADC, or A/D: Abbreviation for analog-to-digital converter. A device used to convert analog signals to digital signals.

 

Adapter – Something that adapts; an adapter is used to change one connector type to another.  Typically an adapter refers to a passive adaptation; i.e. a simple physical change in the connection. The signal is not affected. If the signal is changed, it is more appropriate to use the term converter.

 

ADSL - Asynchronous Digital Subscriber Line. See DSL.

 

Ampere - , or amp – the measure of electrical current, named for André-Marie Ampère, a French physicist and one of the main discoverers of electromagnetism. The unit is A, or more commonly, mA (milli-Amps, or one one-thousandth of an amp).

 

Amplification – to boost or increase the strength of an electrical signal. See Amplifier.

 

Amplifier – an electronic device used to increase the power of a signal. The amplifier has one or more inputs, and one or more outputs. The signals coming in are gathered, given a power boost, and sent to the output. Amplifiers are used to send signals a greater distance than they could reasonably travel on their own. Amplifier also refers to a component of an audio/video system that collects line-level signals, processes them, boosts them, and sends the high-level signal to the speakers. In that application, it is sometimes called a receiver, although the amplifier is only one component of a receiver.

 

Analog – a type of signal transmission with an infinite number of values within a specific wavelength. Transmitting and storing analog information requires a great deal of bandwidth and resources. Also, because the values are not discreet, analog signals are more susceptible to interference. However, they are less so to signal loss and often the signal of choice for long distance applications.

 

Antenna – a length of wire, metal rod, or array of metal tubes used to receive radio signal transmissions.

 

Aspect Ratio – relationship in a display between the width and height. See 16:9, 4:3. Aspect ratio is an important consideration when choosing a home theater display. See widescreen.

 

Asynchronous – not synchronized; refers to data communication that does not occur at pre-determined intervals. The time between data segments can be of an arbitrary duration. Most communications between computers and peripherals are asynchronous. Opposite of synchronous.

 

ATA – Advanced Technology Attachment. ATA is a parallel storage interface technology for disk drives and removable media like CD-ROM drives. It was the first technology to integrate the controller onto the drive itself, called IDE or Integrated Device Electronics. Because of this, ATA is also called IDE. However, because many other drive technologies also utilize IDE it is more proper to use the term ATA. ATA supports two drives per channel, one designated as master and one designated as slave. ATA uses a 40-pin ribbon cable which can be bulky and cumbersome to work with, and is one of the things that lead to the development of SATA. After SATA was released, ATA is now more commonly referred to as PATA for Parallel ATA. ATA has evolved over the years to remain viable by increasing the speed of the bus. Typically ATA will be listed with the speed it supports, such as ATA/66, ATA/100, or ATA/133 for 66, 100, and 133 MB/s respectively.

 

Attenuation – an electrical property of a signal, it is the measurement in the reduction of the signal’s strength. Attenuation is measured in decibels, abbreviated dB. It is the opposite of amplification. Attenuation occurs naturally as a signal travels through a wire and if the attenuation becomes too great, the signal becomes unusable. This is why amplifiers are used. Attenuation is also referred to as signal loss.

 

Audio – of or relating to the transmission or reception of sound.

 

A/V – Stands for Audio/Video. Refers to a system that generates both sound (audio) and picture (video). Cables to connect this type of equipment are sometimes referred to a A/V Cables.

 

AWG – Stands for American Wire Gauge.  A measurement of the size or thickness of a wire.  The larger the number, the thinner the wire.  This standard was developed from a series of measuring gauges made in the 1850s by a Rhode Island manufacturer named Brown & Sharpe.  See the AWG conversion chart here.

 

B         (back to top)   

 

Backbone – see bus.

 

Backward compatibility – of or relating to a device or technology that is compatible with versions that came before it. 

 

Balanced – A type of signal transmission. A balance signal typically employs two conductors per signal. One is the signal itself (called “hot”) and the other is a signal that is of opposite polarity (called “return”). Usually this polarity is measured in relation to a common ground. In a similar fashion to differential, balanced signals are able to greatly reduce interference, because the signal is derived from comparing the two signals. Any voltage difference in the signal (due to noise or signal loss) will also occur is its opposite, so the actual signal can be subtracted from the mix. Balanced signals are very popular with professional audio cables such as those used for microphones, mixing consoles, etc. XLR is the most common connector for balanced applications.  

 

Banana plug – a single pin connector that bulges in the middle (like a banana) used primarily for speaker connections. Banana plugs connect to binding posts. 

 

Bandwidth – a measure of the amount of data that can be transmitted in a fixed amount of time. Digital signals are measured in bits per second (bps), whereas analog signals are measured in cycles per second, or Hertz (Hz).

 

Baseband - A method of communication in which a signal is transmitted at its original frequency. Opposite of broadband.

 

Baud rate – used to refer to the number of bits per second when only one bit is sent per clock cycle. 300 baud = 300 bits per second (bps). Today, most transmission systems are capable of sending more than one bit per clock cycle, so the term bps (bits per second) is used instead.

 

Bend radius – the smallest radius a cable can bend before attenuation occurs.

 

Bi-directional – refers to a parallel printer interface that sends data in two directions; both from the computer to the printer, and from the printer to the computer. Bi-directional signals are used to increase transmission speed, and to allow the printer to report status information such as ink levels or error messages.

 

Binding post – a type of speaker jack. Binding posts have a female jack for banana plugs, and also have a screw terminal for the connection of bare wire or spade lugs.

 

Bit – Binary Digit – The smallest unit of digital information. A bit represents a single value, usually a 1 or a 0. Bits are usually arranged into more meaningful values by combining them into larger units. See Byte.

 

BNC – a type of connector that uses a twist and lock type of retention. No one knows what BNC stands for, but there are several theories, including British Naval Connector, Bayonet Nut Connector, and Bayonet Neill Concelman (named for the alleged creators of the connector). Of the three, the latter seems to be the most feasible. BNC connectors terminate to coaxial cable and are commonly used with video and radio communication equipment, and also older Ethernet networks.

 

Booster – see amplifier.

 

BPS (bps) – bits per second; the number of digital bits sent per unit of time (one second). Used as a measurement of digital data transmission speed.

 

Breaking strength – the pulling force, expressed in pounds, that will cause a conductor to fracture.

 

Broadband - A method of communication in which a signal is transmitted by being impressed to a higher frequency carrier wave. This allows more data to be carried for a longer distance.

 

Bulk – Used to refer to cable or items that are purchased in large amounts. Bulk cable is cable sold in a large roll, typically in 100 ft or higher increments. Bulk cable can also refer to raw, unfinished cable (a cable with no connectors).

 

Bus – the highway on which data travels. The bus is the physical medium that carries the data, typically a cable. In networking, it is also called a backbone.

 

Byte – 8 bits combined into a logical unit. A byte typically represents a single character in a computer system such as the letter “A” or the number “4”.

 

C         (back to top)

 

CRT – Cathode Ray Tube. A type of display that consists of a large vacuum tube, with a screen at the front and an electron gun at the rear. The screen is coated with tiny particles called phosphors that glow when excited by a beam from the electron gun to produce the image. CRT’s are also called direct-view and is the type of display that most people consider when thinking of a TV or computer monitor.

 

Cable – A system for carrying a signal from point to point. A cable is typically made up of individual conductors and a connector at each end. Specific cable types are generally required for specific signal types.

 

Capacitance – an electrical characteristic of a cable. It is a rating of a cable’s capacity to store electricity and is measured in picofarads per foot (pf/ft). As an electrical signal passes through a cable, the cable itself becomes “charged” by the signal. The longer a signal has to move across the wire, the higher this charge becomes. At a certain point, the charge becomes significant enough to actually interfere with the signal itself. Therefore, lower capacitance is desirable as it allows the signal to go further before the “charge” becomes significant. The unit “Farad” is named for Michael Faraday, the discoverer of electromagnetic induction.

 

Case – The chassis or “box” that all of a computer’s components are stored in.

 

Case Mod – Mod, short for modification. A Case Mod therefore is some type of product or process used to modify a computer case. “Case Modding” is currently a popular hobby with technology and computer gaming enthusiasts.

 

CATV – Cable Television. Refers to equipment or technologies used to transmit, receive, or carry cable television signals. CATV cables typically use the F-type connector terminated to 75 Ohm coaxial cable.

 

CCTV: Closed-Circuit Television. A system where video (and sometimes audio) is directly transmitted to specific users and not broadcast to the general public. Most often used for security systems.

 

Centronics – Standard parallel interface used for printers and other parallel peripherals named for the company that developed it, the Centronics Corporation. The printer interface used was a 36-pin connector with two rows of facing contacts on either side of a spaced channel, and used a bail-lock type of retention. The term “Centronics” has come to be used for any connector with that configuration, regardless of the number or contacts or the application.

 

Chrominance – The color part of a video signal. Also called “C”.

 

Cladding - Material that surrounds the core of an optical fiber. It blocks the light from “leaking” out of the core, causing the transmitted light to travel down the core.

 

Client – a computer on a network. A client is a computer or application that relies on a server to perform some operation. See Client/Server.

 

Client/Server – A network architecture which dedicates each computer on the network as a client or a server. Clients rely on servers for resources, such as files, devices, and even processing power. Client/Server architectures are typically more expensive and complex, but they have distinct advantages over peer-to-peer networks. Having files in a central location, for example, makes them easier for all the clients to access and makes it easier for them to be archived. Putting shared devices on a server (such as printers) saves cost by allowing multiple clients to share that single device. Running applications for a central server saves costs because the client machines do not have to be as powerful as the server machine.

 

Coaxial – or, coax – A type of cable composed of a center conductor inside a metal tube or shield. A dielectric material separates the center conductor from the shield, which is covered by an insulating jacket. Coaxial is a popular cable for video because it is highly resistance to signal loss and interference, and can carry a large amount of bandwidth.

 

Comb Filter – An electronic circuit in a display device that separates a composite video signal into its chrominance and luminance counterparts so those signals can be processed. Comb filters can add distortions or artifacts to the video signal which is why technologies that bypass the comb filter like S-Video and Component Video are used.

 

Component Video – This is one of the highest quality types of analog video signals, and is the most common used for Hi-Definition Television (HDTV). Component Video separates the signal into three elements or components; the luminance or picture signal, and two color signals. The three signals are carried on their own conductor, so Component Video cables are three cables with RCA or BNC connectors colored Red, Green, and Blue.

 

Composite Video – The lowest common denominator video signal, found on virtually all consumer grade video hardware today. Composite Video combines all the picture information into a single signal. The connector type used is RCA, and it is typically colored yellow.

 

Computer – a device used for the generation, storage, and retrieval of electronic documents. Typically consists of the computer box itself (also called the case or CPU), an input device such as a keyboard and mouse, and an output device such as a monitor or printer.

 

Conductor – In electrical terms, a conductor is a material that allows electricity to flow freely. In cable terms, the conductor is the physical medium that carries the signal. A cable is typically made up of individual conductors. Copper conductors carry an electrical signal over a single or multiple strands of metal threads. Fiber conductors carry a beam of light over a single or multiple strands of plastic or glass threads. 

 

Connector – The physical means by which two things are joined together, both electrically and mechanically. A connector is typically a physical housing that contains a number of contact pins. A plug connector is typically called a male connector, and a socket, receptacle, or jack connector is typically called a female connector. See Gender. The plug is inserted in the socket, making both an electrical contact and a means to hold the cable in place (the mechanical connection, also called retention).  Both the electrical and mechanical junctions are important. If the cable falls out, it can’t carry signals; if the electrical connection is bad, the mechanical connection doesn’t do any good.