Computer Networks

Computer Networks :

Computer networks means having a group of computer systems connected to each other through communication channels.
They are used to ease communication via e-mails, messaging, and many other communication programs. Computer networks enable two or more people to share the same hardware, such as printers, scanners. What is more, is that they allow to share softwares or operating programs on remote systems. And make information easier to access and manage among the users of the network. There are many types of networks and the most common networks are Local Area Networks (LAN) , Wide Area Networks (WAN), etc..

Local Area Networks (LAN):

It is a network that is confined to a relatively small area, such as a school, library, building. It is owned and maintained by a single organization. Computers connect to each other through a *Network Switch. LANs have very high speed, which is about 1000 mbps. It also have a high data transfer rate .
LANs have fewer problems associated with, and they have less number of systems.

Wide Area Network (WAN):

WANs cover large areas like cities, nations. One of the most important examples of WANs is internet. WANs have less speed than LANs, their speed is about 150 mbps. Computers connected to WANs are often connected through public networks, like telephone system and satellites. WANs experience more data transmission errors if compared to LAN, this is because of the huge number of users of WAN at the same time. Maintaining WAN is difficult because of its wide area that it is covering, and it costs a lot more than LANs cost. WANs is way more congestive than LANs. Almost all people in each region or state are using one WAN.

(*)is a computer networking device that connects devices together on a computer network, by using packet switching to receive, process and forward data to the destination device.
Networks have 3 typical architectures:
1- Client-server:
It is an always-host server, which has a permanent IP address. The clients communicate with the server, they might have dynamic IP addresses, and they do not communicate directly with each other.
2- Peer-to-peer (P2P):
It is no always-on server, and peers are intermittently connected and the IP addresses change, it is highly scalable but difficult to manage.
3- Hybrid of client-server and peer-to-peer (p2p):
It is p2p when users are chatting with each other. But when it comes online, the users register their computers' IP addresses with the central server, and the same user asks central server to find his buddies IP addresses.

Questions :
1-How long did it take to join the internet wires underground?
2- Is it possible that in the upcoming years we will see that the internet will work without physical connections?
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