1.3 Networks, Connections And Protocols Flashcards
LAN
A Local Area Network covers a small geographical area. All the hardware for the LAN is owned by the organisation that uses it.
WAN
A Wide Area Network is a network that connects LANs. Organisations hire infrastructure from telecommunications companies.
NIC
A Network Interface Controller is an internal piece of hardware that allows a device to connect to a network.
Switch
Switches connect devices on a LAN. Switches receive frames of data from devices and transmit this data using the MAC address.
Router
Routers are used to transfer data packets between networks. Routers receive data packets and use the IP address in the packet to determine the best route to transmit the data. Data is transferred from router to router across the internet towards its destination.
Ethernet cable
An ethernet cable connects your device to a network. Ethernet cables are ‘twisted pair’ cables containing four pairs of copper wires.
Coaxial cable
Coaxial cables are made of a single copper wire surrounded by a plastic layer or insulation and a metallic mesh which provides shielding.
Fibre optic cable
These cables transmit data as light. They are high performance cables and therefore expensive. They can transmit data over very large distances.
Bluetooth
Bluetooth provides a direct connection between two devices so that the data can be shared. It has a low bandwidth and the range is typically 10 metres.
WI-FI
Wi-Fi can be used by multiple devices to connect to LANs at the same time. It has high bandwidth compared to Bluetooth. It has a range of between 40-100 metres.
WAP
A Wireless Access Point is a hardware device that allows wireless capable devices to connect to a wired network.
Client-Server
A client-server network is managed by a server. The devices connected to it are clients. Files and software are stored centrally. Clients sends requests to the server.
Peer-to-peer
In P2P networks all devices are equal, connecting directly to each other without a server. Files are stored on individual devices and can be shared with others.
Star topology
In star topology all devices are connected to a central switch or server. The central switch allows many devices to access the server simultaneously.
Mesh topology
In a mesh topology there is no central connection point. Instead, each node is connected to at least one other node and usually more than one.
Network protocol
A network protocol is a set of rules for how devices communicate and how data is transmitted across a network.
MAC Address
Each device needs a unique identifier so it can be found on a network. MAC address are assigned to all network devices by the manufacturer.
IP address
IP addresses are used when sending data between networks. IP addresses are assigned either manually or automatically before the device can access the network.
TCP/ IP
TCP sets rules about how devices connect. It splits data into packets and reassembles the packets back to the original data. The IP directs packets to their destination.
HTTP/ HTTPS
Used by web browsers to access websites and communicate with web servers. HTTPS is more secure as all data is encrypted.
FTP
File Transfer Protocol used to access, edit and move files between devices on networks.
POP
Post Office Protocol used to retrieve emails from a server. The server holds the email until you download it, it is then deleted from the server.
IMAP
Internet Message Access Protocol used to retrieve emails from the server. The server holds the email until you delete it - you can only download a copy.
SMTP
Simple Mail Transfer Protocol used to send emails. It is also used to transfer emails between servers.
Layers
A layer is a group of protocols which have the same function. Layers are self-contained - protocols don’t need to know what is happening in other layers.
Internet
The internet is a network of networks. It is a WAN which is based on the TCP/IP protocol. It connects devices and networks across the world.
Worldwide Web
The WWW is a collection of websites that are hosted on web servers and accessed using the HTTP protocol.
Domain Name Server
DNS translates a website’s domain name onto its IP address. The internet has a network of domain name servers so you don’t need to remember IP addresses.
Cloud
The cloud refers to software and services that run on the Internet, instead of locally on your computer.
Hosting
In order to let other people see your website, it will be hosted on a web server. This is known as hosting. The web server is referred to as the host.
HTTP
HyperText Transfer Protocol is used for sending and receiving web pages
HTTPS
HyperText Transfer Protocol-Secure is used for secure sending and receiving of web pages where data is encrypted
FTP
File Transfer Protocol is used to transfer files between a client and server
POP
Post Office Protocol is used to receive emails. They are deleted off the server once downloaded
IMAP
Internet Message Access Protocol is used to receive emails. They are kept on the server and not deleted.
SMTP
Simple Mail Transfer Protocol is used for sending emails, including between servers.
TCP
Transmission Control Protocol divides data into smaller data packets and adds a sequence number and error correction. To receive data, the packets are examined for errors, the error is fixed or a request is sent for the packet to be resent, the data is reassembled.
IP
Internet Protocol adds a destination address as well as its own address so it accepts data with its own address and ignores data packets that do not contain its own address.
