Networking and Internet Basics - Computing Fundamentals - page 204

Intranets and Extranets
Some organizations have a part of the network that can only be accessed
from within the organization. This sub-network is known as an intranet .
The network administrator may enable intranet users to share message
board items, link to external web pages, and comment on photos or
news items that are posted. The intranet cannot be accessed by anyone
outside the organization and can't be accessed when staff are not physi-
cally located in the office unless they are given specific permission for
remote access.

intranet A special network that only staff within
the company network can access. For security
reasons, an intranet can only be accessed onsite
and not remotely.

In contrast, a company may maintain an extranet , a separate network
that is specifically intended for people outside the organization. An
extranet may be used by the company's business partners, contract
employees, or customers to get real-time information, such as about
products it supplies that might soon need restocking.

extranet A special network set up by a business
for its customers, staff, and business partners to
access from outside the office network; may be
used to share marketing assets and other non-
sensitive items.

Ethernet
Over the years since networking began, there have been several popular
networking technologies—that is, different sets of standards for net-
working hardware and software. All of those technologies have become
obsolete except Ethernet . Most network hardware that you buy in
stores today can be assumed to be Ethernet-compatible unless it specifies
otherwise.

Ethernet The current dominant standard for local
area networking devices.

Ethernet can technically be either wired or wireless, but it is becoming
increasingly common to refer to only the wired type as Ethernet; wireless
Ethernet is popularly called Wi-Fi . (See the following section for more
information about Wi-Fi.)

Wireless Networking Technologies
A network can connect devices using either wired or wireless connec-
tions. A wired connection runs a cable between the points, whereas wire-
less connects the two points via radio frequency (RF) or infrared.

Wireless communications have two main uses. The first use is at the
endpoints of network connectivity, where a device such as a smartphone
or laptop computer connects wirelessly to a router or other device that
provides network and/or Internet access. The second use is as a source
of transferring data between locations when using cables is not practical,
such as with satellite and microwave systems.

A single network can contain a mixture of wired and wireless connections, as long as they are the same
network technology. For example, if you have a router in your home through which all the computers share an
Internet connection, some of the computers can connect to it with wired Ethernet and others can connect to
it via Wi-Fi. Because they all share a common network technology (Ethernet), they work together seamlessly.
However, networks using different technologies cannot communicate with one another. For example, you can't
use a Bluetooth device to connect to an Ethernet network.

NOTE