Computer Science revision
Network fundementals
Network hardware
Network basics
Networks vary in size and complexity, some connected more devices and communicating more, whereas some are simple, like a phones hotspot
A network is a group of devices connected together, wirelessly or with cables to communicate with each other.
People use networks to share data, and communicate with each other, through text messages (sms) emails, or telephone messaging and calling.
Sharing hardware devices such as printers means everyone can use it, without them all having to have a printer. Be cautious and secure devices well though, to prevent unwanted others to access it. Shared files must also be secured, setting the right permissions and sending them to the correct people
A network allows data backups, which makes a replication of the file incase something happens to the file, such as corruption or theft.
Networks also allow computers to access multi-user systems, such as school attendance databases.
Networks also allow updates or changes to be pushed out from one device, such as the IT department.
To connect to a network, you need a network interface card, and the type of network you are attempting to link to.
Network can be managed remotely, but you need to think of what network topology will be used, how many devices will be connected, and the security of the network.
The advantages of networks is the ability to share files, information, to communicate quickly, the ability to centrally backup files, the ability to share hardware, the ability to push software updates. Some disadvantages though is extra hardware for cabling, and greater security risks.
Types of networks
Low area network (LAN) connects devices in a small area like a household, usually through cables.
Wide area networks (WAN) connects devices all over the world usually through the internet wirelessly.
Network topologies
Bus topologies use one single backbone cable to connect all the devices.
Ring topologies connect multiple devices via a server in a ring like way, usually using cables.
Star topologies branch from a switch, and multiple other devices connect to it
Mesh topologies connect all devices together, meaning if one of the connections fails, there are still many more to use.
Network hardware devices
Network interface controllers (NICS) are used to connect a device to a network. It converts data into digital signals, which can be sent across the medium. At the receiving end the NIC converts the signals back into data.
Hubs and switches are used to relay data, hubs are inefficient due to them sending the data to every device on the network.
Switches only send the data to their intended destination.
Routers are used when there is communication between two different networks. Routers typically also provide our device with internet, and are normally household ISPs, internet service providers. core routers can forward packets along the backbone of the internet.
Network cables
Unshielded twisted pair cable UTP also known as an ethernet cable, are a very common cable for devices. They contain twisted copper cables, which send electrical signals, held with a simple plastic outer casing.
Fibre-optic cables are mirror ended cables that let light travel through them, that light signal is our data. The data can travel up to 100km, making them great for interconnecting cities.
Coaxial cables are very simplistic, and are used mostly for low-definition television signals. It is made of a copper conductor, surrounded by insulation, a braided outer conductor and finally a PVA insulation.