Computer
The computer is one of
the basic pillars on which the world today depends in a basic situation where
students, employees, companies, government institutions and a large number of
humanitarian and non-humanitarian organizations benefit from it. The process of
obtaining a computer in this age is an obvious one that must be found in Every
home and every institution so that the institution can promote itself and adapt
to the world around it in harmony, harmony and relaxation.
After the widespread use
of computers in every home, institution and university it became very important
to make the connections between these computers to take advantage of their
information quickly and accurately, it was necessary to find the term computer
network that connects computers in one place, But that network is limited to a
specific place or number of computers that are connected to each other to
enable communication and file transfer between them with ease and convenience.
Types of
computer networks
Computer networks are an
essential necessity in today's fast-paced world. Networks vary according to
their size to three main types:
·
Small
household: (LAN) which is limited to a number of devices
located in places very close to each other.
·
Long-distance
networks (WANs): which are between two or
two cities and sometimes even two continents, sometimes a network of a
particular company, or a company providing network service to another company,
such as Internet companies that transport the Internet from one country to
another, Link the world to each other for a nominal service fee that you
receive from each user.
·
The
Personal Network (RAN): A network that belongs
only to one person who connects his various devices, such as those who work in the
field of design or physical and astronomical research; they need a number of
interconnected devices to do their work on the right side.
These three types of
months are the most common types of computer networks according to the size of
the network, the number of devices connected to the network, and also may be
considered dependence on the distance between the devices associated with that
network.
·
Civil or
Urban Network (MAN): A network that is larger
than a home network and smaller than a wide-area network, usually covering a
city or a part of it. This network is designed to make users using devices in a
single city benefit from high speed and performance The good that this network
has.
Forms of
networks
Networks are designed in
different forms to perform certain functions to benefit the user well, and
these differ in the functions and the distribution of network devices and the
cost of financial, these forms are:
·
Star: This shape is similar to the five - pointed star, in the middle is
located a central device used by other devices in the network and organize
communication between them, and if it has a malfunction, the network completely
stops working. The cost is quite high; because of the central system which
requires that the specifications are high and very good to withstand pressure
and perform tasks efficiently.
·
annular:
a network that is shaped just like the circuit,
each device connected to the device after and before, and the devices in this
form a closed loop. This is one of the least-used species due to poor
performance in this format, and the relatively average cost.
·
linear: This form of the most widespread and widespread because of its
relatively low cost, and the devices in this form connected to each other
through a single line of communication, but the performance is not desirable
now because the linear form does not allow two devices to send information in
At the same time, it only allows one device to use the main line, after which
the device starts following it, and so on.
·
Mesh
(Mesh): the best forms of networks, and the highest
quality and efficiency in performance. Each device is connected to all other
devices in the network. If a communication line fails, there are other ways to
access the device, but the cost of designing this format is very high because
of the very large number of cables used to connect each device to all other
devices in the network.
Classification
of networks
Computer networks can
also be classified according to the interconnection method. There are three
main types of networks in this area: wired (Wired), which is interconnected by
wire, either with copper wires or Fiber Optics. A wireless network may be based
on radio-wave interconnection between networks. Advanced networks, which are
satellite networks that are connected by satellite signals to Earth, are the
most accurate She cried and hurried on the ground.
Network
protocols
For networks to operate
regularly and accurately, so-called protocols should be used to exchange data
accurately. The protocol is defined as laws that govern the way, quality, and
form of data exchange between networks and devices in general. Not all devices
operate on a single operating system, and not all networks use the same
protocol between their communication devices.
The protocols work as an
interpreter between different contacts that use a different operating system
than the rest of the contacts. The networks rely primarily on two basic
protocols: Transmission Control Protocol (TCP) and IP (Internet Protocol)
Computer networks are a genius invention that has provided the world with a lot
of benefit. It has facilitated the sharing of information across the globe and
made the world It seems like a small village, and it has been able to create
very strong links between users of networks and between the world in all its
parties and peoples, leading to the exchange of cultures and knowledge.