Computer Networks
Networks are collections of computers, software, and hardware that are all
connected to help their users work together. A network connects computers by
means of cabling systems, specialized software, and devices that manage data
traffic. A network enables users to share files and resources, such as printers,
as well as send messages electronically (e-mail) to each other.
Computer networks fall into two main types: client/server networks and
peer-to-peer networks. A client/server network uses one or more dedicated
machines (the server) to share the files, printers, and applications. A
peer-to-peer network allows any user to share files with any other user and
doesn’t require a central, dedicated server.
The most common networks are Local Area Networks or LANs for short. A LAN
connects computers within a single geographical location, such as one office
building, office suite, or home. By contrast, Wide Area Networks (WANs) span
different cities or even countries, using phone lines or satellite links.
Networks are often categorized in other ways, too. You can refer to a network by
what sort of circuit boards the computers use to link to each other – Ethernet
and Token-Ring are the most popular choices. You can also refer to a network by
how it packages data for transmission across the cable, with terms such as
TCP/IP (Transmission Control Protocol/Internet Protocol) and IPX/SPX (Internet
Package eXchnage/Sequenced Package eXchange).
What is Anti-Virus?
Answer:
Anti-virus is the name given to software that detects and (where possible)
removes viruses from messages. By removing viruses at the email server, all
internal mail clients are protected AND all customers are protected from
receiving viruses too.
Computer Viruses are written by people who wish to gain control of your system
resources and are continually updated to try and break through any barriers you
may have installed. GMS Anti-Virus overcomes this issue by providing a
"signature file" update service which ensures that all new varients are caught
as soon as possible.
"Antivirus" is protective software designed to defend your computer against
malicious software. Malicious software, or "malware" includes: viruses, Trojans,
keyloggers, hijackers, dialers, and other code that vandalizes or steals your
computer contents. In order to be an effective defense, your antivirus software
needs to run in the background at all times, and should be kept updated so it
recognizes new versions of malicious software.
Also Known As: anti-virus, anti virus
Wireless Modem.
Wireless modems are devices that allow computers to connect to a wireless local
area network (WLAN) without physical cabling such as ethernet wiring. Wireless
modems use cellular, satellite or WiFi protocols to connect to a WLAN, which can
then provide Internet service. This differs from dial-up and DSL modems which
use telephone lines to connect to the Internet, while cable modems use cable TV
lines for connectivity.
For mobile applications, a PCMCIA wireless modem card in a laptop can provide
access to the Internet through public "hotspots." These are geographical areas
where WLANs allow public Internet access via wireless modems. In some cases a
small membership fee is required, while other hotspots are free.
Various wireless networks use proprietary protocols, and wireless modems are
certified as compatible with certain architecture(s). Some protocols, like CDPD
(Verizon), GPRS and EDGE (AT&T and Cingular), are even slower than dialup; while
Cellular UMTS (AT&T) and 1xRTT (Verizon) wireless networks can operate at about
300 kilobits per second (kbs). A newer cellular flavor offered by Verizon and
Sprint, EVDO, advertises speeds of 400-700 kbs, rivaling broadband packages.
Future technologies including Cingular's HSDPA and Verizon's EVDV promise even
greater speeds.
Another popular network for mobile wireless modems is WiFi (Wireless fidelity),
which can operate at a respectable 400 kbps. WiFi is used in many Internet cafés
and other hotspots. WiFiMax is a newer standard that offers even faster speeds
and more features.