Glossary of Terms

Glossary

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 

A

ActiveX - A set of technologies created by Microsoft that enables interactive content on Web sites. Our in-house developed applications may sometimes require download of a small ActiveX program. This is entirely safe.

ADSL (Asynchronous Digital Subscriber Line) - A telephone line with uneven transmission rates, half the transmission (upstream) can attain speeds of up to 640Kbps, the other half (downstream) can acheive 2,048Kbps or greater.

Applet - A small Java program that can be embedded in an HTML, or web page. Applets differ from full-fledged Java applications in that they are not allowed to access certain resources on the local computer, such as files and serial devices (modems, printers, etc.), and are prohibited from communicating with most other computers across a network. The common rule is that an applet can only make an Internet connection to the computer from which the applet was sent. Network Webcams Ltd uses Java applets as part of its set of tools.

B

Bandwidth - The data transfer capacity available on a given line to the internet. Typically the downstream data transfer capacity.

Built-in Motion Detection - Cameras equipped with built-in motion detection can identify any motion or change in live video based on user-set sensitivity levels. Advanced cameras can be set to e-mail images or video showing the motion or change detected.

C

CCTV (Closed Circuit Television) - Despite its name, CCTV is not television! It does not broadcast TV signals but transmits them over a closed circuit through electrically conducting cable or wireless transmitter and reciever.

CCD - Charge-Coupled Device - Electronic memory in which metal oxide semiconductors are arranged so the charge from one semiconductor is the input of the next semiconductor. CCDs can be charged by light or electricity. One use is for storing images in digital cameras, video cameras, and optical scanners. Network Cameras that employ CCD technology typically cost more than analogue cameras.

D

Data compression - A process that reduces the file size for processing, storage, transmission, and display. Compression may be lossless (e.g., CCITT) or lossy (JPEG). The quality of the image may be affected by the compression techniques used and the level of compression applied.

DNS - Domain Name System - The system for translating web addresses to IP addresses. For a device to contact a web or FTP server using its domain name it must first obtain a corresponding IP address from a local DNS server. ISPs will provide two DNS servers, a primary and a secondary.

E

Ethernet - A very common method of networking computers in a LAN. Ethernet will handle about 10,000,000 bits per second and can be used with almost any kind of computer.

Embedded Operating System - Network IP Cameras that use an embedded operating system, such as Linux, operate as both cameras and computers. Cameras with embedded operating systems can perform advanced functions, such as the ability to send images to a web site via FTP; simultaneous access by multiple users and e-mail notification.

F

Firewall - A combination hardware and software buffer that many companies or organizations have in place between their internal networks and the Internet. A firewall allows only specific kinds of messages from theInternet to flow in and out of the internal network. This protects the internal network from intruders or hackers who might try to use the Internet to break into those systems.

FTP - File Transfer Protocol - Network cameras equipped with an embedded operating system, such as Linux, can use FTP to send images to a web site.

G

No terms are yet available for this letter.

H

H.263 - A standard video-conferencing codec. As such, it is optimized for low data rates and relatively low motion. H.263 is an advancement of the H.261 standard, mainly. It was used as a starting point for the development of MPEG (which is optimized for higher datarates.)

HTTP (HyperText Transfer Protocol) - The protocol for moving hypertext files across the Internet. Requires a HTTP client program on one end, and an HTTP server program on the other end. HTTP is the most important protocol used in the World Wide Web .

I

ISDN (Integrated Services Digital Network) - Digital telephony scheme that allows a user to connect to the Internet over standard phone lines at speeds higher than a 56K modem allows.

IP (Internet Protocol) - the most basic protocol to communicate on the Internet. An IP number is a numerical address consisting of four numbers seperated by full stops. Each IP address uniquely identifies a certain computer on the Internet. Domain names are used to make using them easier.

IP Storage - A generic term for a method of storing images and video on hard disc recorders connected to a LAN or the Internet.

J

Java - A computer programming language invented by Sun Microsystems. Using Java, Web developers create small programs called "applets" that allow Web pages to include animations, calculators, scrolling text, sound effects and games. See also Applet

JavaScript - Popular client-side scripting language originally developed by Netscape. Commonly used to make static HTML documents more interactive. Despite its name, JavaScript is not related to Java.

JPEG - Joint Photographic Experts Group. Together with GIF, JPEG (or JPG) is one of the two commonly used image formats on the Web. JPEG format is best suited to photographic images, and, of course, webcams!

K

No terms are yet available for this letter.

L

Local area Network (LAN) - A computer interconnection network for limited connection distances, like those of an office environment.

Leased Line - A leased line is a transmission line reserved by a communications carrier for the private use of a customer. Examples of leased-line services are 56Kbits/sec or T-1 lines.

Linux - Linux is an open source operating system within the Unix family. Because of its robustness and availability, Linux has won popularity in the open source community and among commercial application developers. Camvista uses the flexibility and power of Linux to drive its tools and applications.

M

Mpeg - The acronym for Moving Pictures Expert Group, MPEG is an international standard for video compression and desktop movie presentation. A special viewing application is needed to run MPEG files on your computer.

Multiplexer - These units are high-speed switches that provide full-screen images from up to 16 cameras. Multiplexers can playback everything that happened on any one camera without interference from the other cameras on the system.

N

Network camera - Cameras are attached through an Ethernet connection (or router) and power source, so you don't need a computer at each location you want monitored. Each camera has a built-in web server with IP address. To view the images on a PC, simply open a graphics-capable Web browser and type in the cameras specified, password optional Internet address.

O

No terms are yet available for this letter.

P

PING - Loosely translated, ping means ?to get the attention of? or ?to check for the presence of? another party online. Ping operates by sending a data packet to a designated address and waiting for a response. The computer acronym was contrived to match the submariners' term for the sound of a returned sonar pulse.

Professional Webcam System - A business strength webcam designed to offer features useful for business use and built to be far more reliable than ordinary home webcams.

PSTN - Public Switched Telephone Network. PSTN is a name for the public fixed telephone network

PTZ (Pan, Tilt & Zoom) - A term to define a controllable camera. Describes the three directions in which control can be made - pan (left to right), tilt (up and down) and zoom (in and out).

Q

No terms are yet available for this letter.

R

Remote access - A broad term meaning the ability to log on to a network or resource from a distant location. Generally, this requires a computer, a network connection and remote-access software to allow the computer to connect into the network.

Remote Monitoring - The process of viewing and/or recording live images and video footage from a remote location, typically for surveillance purposes.

Resolution - A measure of how clear and crisp an image appears on a monitor. As each piece of CCTV equipment included within a system contributes to the overall image quality, the resultant image can only be as clear as the piece of equipment with the lowest resolution. If you are using a high-resolution monitor together with a low-resolution camera, the monitor can only display low-resolution images. This observation becomes increasingly important when using the system for webcams and recording.

Router - A special-purpose computer or software package that handles the connection between 2 or more networks. Routers spend all their time looking at the destination addresses of the packets passing through them and deciding which route to send them on.

S

SMTP - Simple Mail Transfer Protocol

T

TCP/IP - the collection of "protocols" underlying the functioning of the Internet. Each computer connected to the Internet is identified by a unique IP Address.

U

UNIX - An operating system, commonly used on the backbone machines on the Internet. Most Web servers are run under the UNIX operating system.

URL - Uniform Resource Locator. An ?address? on the network or Internet like http://www.mysite.co.uk.

V

Video Server - Generally, a device which accepts analog video connections and outputs them as digital video streams. Many video servers can deliver video in a number of ways, including as a video stream or as individually uploaded images.

Video Switcher - Sequentially displays full screen images, one camera after another typically at 3 to 5 seconds intervals. While the image source from one camera is displayed on screen the other camera sources are not being recorded.

W

Webcam - Generally, a digital camera designed to take digital photographs and transmit them over the internet. Most webcams require additional PC software to operate. Traditionally, these inexpensive lower-end cameras are for home use only. Businesses considering a webcam presence should opt for a more robust and reliable network camera option.

Webcam (professional) - Professional webcams use industry standard CCTV or video equipment to present high quality images and video for distribution via the Internet. Network Webcams Ltd offer only these professional systems.

Wireless (WiFi) - A local area network that uses high frequency radio signals to transmit and receive data over distances of a few hundred feet; uses ethernet protocol.

X

No terms are yet available for this letter.

Y

No terms are yet available for this letter.

Z

No terms are yet available for this letter.