Basics Flashcards
Computer network
A computer network is when two or more computers are connected together to allow them to communicate.
protocol
Communication rules in order to pass on a message successfully. E.g. @ symbol is needed for email addresses. http://www or https://www is needed for a web address.
Network cable
Used to connect together different devices. They have plastic plugs that connect into sockets on devices. The cable is made up of a number of copper wires. Data can be sent in both directions across a cable.
Hub
A hub connects a number of computers together. Ports allow cables to be plugged in from each connected computer.
Router
A router is used to connect a network to another network over a large area. A router forwards messages from one network to another. It acts as a gateway. A common job of a router is to join a home network to the internet via an internet service provider (ISP).
server
A server is a powerful computer which provides services. There are many different types of server, for example, a file server which stores files (i.e. text, images, sound, or video) that can be accessed by all devices on the network.
Wired connection
Wired networks send data along ethernet cables. (See the PPT for the advantages and disadvantages of wired networks)
Wireless connection
Wireless networks send data through the air using radio waves. E.g. Bluetooth, WiFi, 4G and 5G. (See the PPT for the advantages and disadvantages of wireless networks)
Bandwidth
Bandwidth is the amount of data that can be moved from one point to another in a given time. Higher bandwidth = more data per second. More bandwidth DOES NOT increase the speed. See bps below.
bps
bps = bits per second.
Bandwidth is measured in bits per second. A bit is the smallest unit of data. Data transfer rates are now so good that bandwidth is usually measured in Megabits per second (Mbps). 1 Mb = 1 million bits
ISP
ISP = Internet Service Provider.
ISPs provides individuals, households and companies access to the internet.
Buffering
Data is arriving at your device at a rate that is slower than it is being processed. E.g. when you are watching a film on Netflix and it pauses, and you have to wait for a period of time before it starts again. Indicates that more bandwidth is required
Internet
The internet is a worldwide network of computers. It is the physical hardware, e.g. the cables, the routers, and other pieces of hardware used to connect devices together. Any device connected to the internet is part of this network.
Ocean internet cabling
Internet cables that lie on the seabed that connects continents. 99% of internet data is transmitted through cables under the oceans.
packet
Networks send and receive messages in small units of data known as ‘packets’. A single message may be too large to fit in one packet. It is often split into many packets. Each packet contains a part of the message, an address of where it came from, and an address of where it is going. These addresses are known as ‘IP addresses’, and they are unique.
IP address
IP = Internet Protocol.
An IP address is made up of 4 groups of numbers between 0 and 255, each separated by a full stop. These are unique for every device on the internet. Typically, this would be the address of the router that connects to the internet. E.g. 192.168.5.43
IP
IP = Internet Protocol.
A protocol to route the packets. Each device on the internet has an IP address that uniquely identifies it from all other devices.
TCP
TCP = Transmission Control Protocol.
Splits the messages sent across the internet into smaller pieces called ‘packets’. Assembles the packets in the correct order at the receiver end
Digital footprint
All of the information about us that can be found on the Internet is known as our digital footprint. E.g. records of the websites you visit, emails you send, information you submit to online services.
Metadata
Metadata is data about data. This is additional information that apps and devices exchange along with content, often without the user’s knowledge.
Privacy policy
A statement that explains in simple language how an organisation or agency handles your personal information.
Packet header
A packet ‘header’ is on each packet and it contains:
* Sender IP address * Receiver IP address * Total number of packets * the sequence number of this particular packet When the computer receives the packets, it waits until it has received all of them, and then reassembles the data into the correct order using the sequence number.
