Internet Terminology
Internet
Terminology
ISP (Internet Service Provider)
An Internet
service provider (ISP) is an organization that provides services
accessing and using the Internet. Internet service providers may be organized
in various forms, such as commercial, community-owned, non-profit, or otherwise
privately owned.
An ISP (Internet
service provider) is a company that provides individuals and other companies
access to the Internet and other related services such as Web site building and
virtual hosting. An ISP has the equipment and the telecommunication line access
required to have a point-of-presence on the Internet for the geographic area
served. The larger ISPs have their own high-speed leased lines so that they are
less dependent on the telecommunication providers and can provide better
service to their customers. Among the largest national and regional ISPs are
AT&T WorldNet, IBM Global Network, MCI, Netcom, UUNet, and PSINet.
Intranet
An intranet
is a private network accessible only to an organization's staff. Generally a
wide range of information and services from the organization's internal IT
systems are available that would not be available to the public from the
Internet. A company-wide intranet can constitute an important focal point of
internal communication and collaboration, and provide a single starting point
to access internal and external resources. In its simplest form an intranet is
established with the technologies for local area networks (LANs) and wide area
networks (WANs).
Similarities between Internet and Intranet
·
Intranet uses the internet protocols such as
TCP/IP and FTP.
·
Intranet sites are accessible via the web
browser in a similar way as websites in the internet. However, only members of
Intranet network can access intranet hosted sites.
·
In Intranet, own instant messengers can be used
as similar to yahoo messenger/gtalk over the internet.
Differences between Internet and Intranet
·
Internet is general to PCs all over the world
whereas Intranet is specific to few PCs.
·
Internet provides a wider and better access to
websites to a large population, whereas Intranet is restricted.
·
Internet is not as safe as Intranet. Intranet
can be safely privatized as per the need.
VSAT (Very Small Aperture Terminal)
A very small aperture
terminal (VSAT) is a two-way satellite ground station with a dish
antenna that is smaller than 3.8 meters. The majority of VSAT antennas range
from 75 cm to 1.2 m. Data rates, in most cases, range from 4 kbit/s up to
16 Mbit/s. VSATs access satellites in geosynchronous orbit or geostationary
orbit to relay data from small remote Earth stations (terminals) to other
terminals (in mesh topology) or master Earth station "hubs" (in star
topology).
VSATs are used to transmit
narrowband data (e.g., point-of-sale transactions using credit cards, polling
or RFID data, or SCADA), or broadband data (for the provision of satellite
Internet access to remote locations, VoIP or video). VSATs are also used for
transportable, on-the-move (utilising phased array antennas) or mobile maritime
communications.
VSAT (Very Small
Aperture Terminal) is a satellite communications system that serves home and
business users. A VSAT end user needs a box that interfaces between the user's
computer and an outside antenna with a transceiver. The tranceiver receives or
sends a signal to a satellite transponder in the sky.
The satellite
sends and receives signals from an earth station computer that acts as a hub
for the system. Each end user is interconnected with the hub station via the
satellite in a star topology. For one end user to communicate with another,
each transmission has to first go to the hub station which retransmits it via
the satellite to the other end user's VSAT. VSAT handles data, voice, and video
signals.
VSAT is used
both by home users who sign up with a large service such as DirecPC and by
private companies that operate or lease their own VSAT systems. VSAT offers a
number of advantages over terrestrial alternatives. For private applications,
companies can have total control of their own communication system without
dependence on other companies. Business and home users also get higher speed
reception than if using ordinary telephone service or ISDN.
URL
A Uniform Resource Locator
(URL), colloquially termed a web address, is a reference to a web
resource that specifies its location on a computer network and a mechanism for
retrieving it. A URL is a specific type of Uniform Resource Identifier (URI),
although many people use the two terms interchangeably. URLs occur most
commonly to reference web pages (http), but are also used for file transfer
(ftp), email (mailto), database access (JDBC), and many other applications.
Most web browsers display the
URL of a web page above the page in an address bar. A typical URL could have
the form
http://www.example.com/index.html
,
which indicates a protocol (http
),
a hostname (www.example.com
),
and a file name (index.html
).
Portal
Portal is a term,
generally synonymous with gateway, for a World Wide Web site that is or
proposes to be a major starting site for users when they get connected to the
Web or that users tend to visit as an anchor site. There are general portals
and specialized or niche portals. Some major general portals include Yahoo,
Excite, Netscape, Lycos, CNET, Microsoft Network, and America Online's AOL.com.
Examples of niche portals include Garden.com (for gardeners), Fool.com (for
investors), and SearchNetworking.com (for network administrators).
A number of large access
providers offer portals to the Web for their own users. Most portals have
adopted the Yahoo style of content categories with a text-intensive, faster
loading page that visitors will find easy to use and to return to. Companies
with portal sites have attracted much stock market investor interest because
portals are viewed as able to command large audiences and numbers of
advertising viewers.
Typical services offered by
portal sites include a directory of Web sites, a facility to search for other
sites, news, weather information, e-mail, stock quotes, phone and map
information, and sometimes a community forum. Excite is among the first portals
to offer users the ability to create a site that is personalized for individual
interests.
Website that serves as a gateway or a main entry point
('cyber door') on the internet to a specific field-of-interest or an industry.
A portal provides at least four essential services: (1) search engine(s), (2)
email, (3) links to other related sites, and (4) personalized content. It may
also provide facilities such as chat, members list, free downloads, etc.
Portals such as AOL, MSN, Netcenter, and Yahoo, earn their revenue from
membership fees and/or by selling advertising space on their webpages. Also called
portal site or web portal.
Domain Name Server
Domain Name
Servers (DNS) are the Internet's equivalent of a phone book. They maintain a
directory of domain names and translate them to Internet Protocol (IP)
addresses.
This is necessary because, although domain names are easy for people to remember, computers or machines, access websites based on IP addresses.
Information from all the domain name servers across the Internet are gathered together and housed at the Central Registry. Host companies and Internet Service Providers interact with the Central Registry on a regular schedule to get updated DNS information.
When you type in a web address, e.g., www.smgc.com, your Internet Service Provider views the DNS associated with the domain name, translates it into a machine friendly IP address (for example 216.168.224.70 is the IP for smgc.com) and directs your Internet connection to the correct website.
After you register a new domain name or when you update the DNS servers on your
domain name, it usually takes about 12-36 hours for the domain name servers
world-wide to be updated and able to access the information. This 36-hour
period is referred to as propagation.
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