Network

## Description

A network is when a group of computers and other network capable devices are connected to each other , either directly or through a centralized computer (such as a server) or other network technology (such as a hub, switch, or router) . Networks can vary greatly in size, anything from one device connected directly to another, to the internet where nearly 3.5 billion devices are connected . Networks essentially connect devices and allow them to communicate with each other and also allow resources to be shared (such as application, files and services).

## Types of Networks

There are several different types of networks, and the type of network is often determined by the size of the network and/or what its purpose is as well as function.

### ***Personal Area Network (PAN)***

A PAN is the simplest type of network and also the smallest, as it mainly consists of one user who has one of their devices connected to several other devices. For instance the user's home computer connected to a printer and their smartphone, so that all these devices can communicate with each other when needed, (using the computer to send data to the smartphone or instructing the printer in another room to print a document).

### ***Local Area Network (LAN)***

This is a very common type of network, and is mainly used for small network purposes for fundamental devices (computers, printers, etc.) within a short-range of each other. This can also include buildings that are situated close to each other. This can allow easy sharing of resources and communication between devices. A LAN can consist of anything from two devices to several hundred devices.

A LAN can be connected physically with Ethernet cables or established with wireless technology such as a Wi-Fi router (which can be more cost effective) . This will create a Wireless Local Area Network (WLAN) which can allow easier adding or removing of devices with minimal infrastructure changes, and is more cost effective due to less need for network cabling. LANs can also use additional hardware such as routers to connect with networks on a larger geographical scale

### ***Wide Area Network (WAN)***

This is a much larger network than a LAN, and allows a wider range of device communication, access to resources and sharing of information. WANs can span anywhere from a large organization to cross-country communication and can be used as an intermediary between LANs to allow LAN networks to communicate and share resources over a larger area . Essentially the internet can also be considered as a type of WAN network.

### ***Intranet & Extranet***

This is a private network, usually hosted within an organization, that require authorization to access. Organizations use intranets as a means of internal communication and are often restricted to a specific LAN and are not connected to the internet. This makes them more secure . However, some intranets are linked to the internet to allow users to access them remotely if necessary. This is similar to an intranet except the extranet can also establish connection to a specific external network.

### ***Darknet***

This is a type of network that operates over the internet but requires specialized software to access. In some cases, specialized configurations and authorization may be required as well. A darknet may be private (peer-to-peer) or users can use the Tor Browser for public darknets as conventional browsers such as Google Chrome, or Firefox are unable to reach darknets . The reason darknets usually require complex methods to access is because they are often involved in illegal activities (arms dealing, human trafficking, buying and selling of stolen goods and more). By using non-conventional protocols, ports and programming languages, they cannot be index by other web browsers and make it much harder for authorities to detect and track.

## Security Aspect

Networks have evolved rapidly over the years and have popular targets for attackers. Often attackers try to get their malware onto networks so that they can propagate onto multiple computers at a time. Organizations are dependent on networks to carry out their daily duties, communicate with other individuals and devices, and share information. Attackers may try to get into a network and monitor the network traffic passing through in hopes of capturing sensitive information such as financial or personal information of an individual.

Network protocols are now in place that help secure connections using authentication and encryption. However the biggest security risk to networks is human error. The more users there are on a network, there's a better chance one of them may accidentally fall for a social engineering attack and introduce a malware or trigger a cyber attack on the network. Not all users are well-educated on cyber attack techniques or know how or what to look out for in suspicious emails. This is why it is necessary to educate users on a network of potential threats and how to identify them, and also it is important to implement additional mechanisms to try avoid successful attacks as a result of human error.

## References

1. ↑ https://www.techopedia.com/definition/25597/computer-network
2. ↑ http://www.certiology.com/computing/computer-networking/network-devices.html
3. ↑ http://www.internetlivestats.com/internet-users/
4. ↑ http://searchnetworking.techtarget.com/definition/local-area-network-LAN
5. ↑ https://www.lifewire.com/wide-area-network-816383
6. ↑ https://techterms.com/definition/intranet
7. ↑ http://www.sciencedirect.com/science/article/pii/S1361372309701502?via%3Dihub