computer science PPE

Network

Two or more devices connected together sot that they can communicate with each other.

Name 4 Advantages of networks

• emails can be sent easily and quickly to anyone

• Devices can be shared, ex. Printer, meaning it can be used by many people.

• Files can be shares quickly and easily

• Licenses of softwares on networks can be shared so that it costs less instead of one for each person.

6 Disadvantages of networks

• expensive to set up with the equipment

• No privacy as hackers can easily get into the system because multiple devices are connected.

• Viruses can spread easily to devices on the network.

• If the network stops working, all devices connected will also stop working.

• Security methods are needed to make sure the network is protected

• Need to hire a network manager and staff to make sure it’s working properly.

LAN - local area network

Network that covers a small geographical area and normally owned by a person or organisation.

WAN - wide area network

Network that covers a large geographical area and is not normally owned by a person or organisation. Ex. a business with offices all around the world. And the internet

2 wires used in a wired network :

• ethernet copper wire

• Fiber optic

3 advantages of a wired network:

• speed: fast connection

• Reliability: good performance

• Security: well secured as it is in wires.

3 disadvantages of a wired networks:

• cost is expensive to set up cables and ports

• Not easy to add new ports

• Not flexible as you cannot move around with the computer plugged into a wall

3 advantages of a wireless network:

• tidy: no wires around connecting everywhere.

• Flexible: can go around anywhere in range with the device connected to the network

• Cost is quite cheap.

3 disadvantages of wireless network:

• not secure

• Range is limited

• Speed is slow when more devices are connected.

2 types of topology:

• bus topology

• Star topology

Bus topology

Network which all devices are connected to one single cable

Star topology

All devices have a point to point connection with the host which is the hub and through that they can communicate with each other.

Authentication

Usernames and strong passwords

Encryption

A key that is a code for the words, it stops the hacker from understanding the important or sensitive information that they have hacked into. You need a key to crack the code.

Firewalls

Checks data coming into or out of the network

MAC address

Each computer has an address and the network only allows the devices that have the address that is allowed in the network.

Wireless access point

Uses a wireless radio to allow devices to connect wirelessly to an existing network.

Router

A device which connects two or more different networks together allowing them to communicate with each other.

Switch

A device which provides computers and other devices with a wired connection to a network.

NIC (network interface card)

A component within a computer or other device which allow it to connect to a network. The card provides the physical connection to the network.

Transmission media

The physical connection which carries data between network devices this could be a cable or wireless signals depending on the network.