1.3 computer networks, connections and protocols

Question 1

LAN (local area network)

Answer 1

-small geographic area
-all hardware is owned by the organisation using it
-wired with UTP or fibre optic cable or wireless using routers and Wi-Fi access points

Question 2

WAN (wide area network)

Answer 2

-large geographic area
-infrastructure is hired from telecommunication companies who manage it. Connected with telephone lines, fibre optic cables or satellite links

Question 3

client-server network

Answer 3

-a client makes requests to the server for data and connections.
-A server controls access and security to one shared file store

Question 4

peer-to-peer network

Answer 4

all computers are equal and serve their own files to each other. Each computer is responsible for its own security and backups and usually has its own printer

Question 5

wireless access point

Answer 5

hardware that allows a Wi-Fi-enabled device to connect to a network

Question 6

router

Answer 6

-sends data between networks
-it is needed to connect a LAN to a WAN. It uses the IP address on a device to route traffic

Question 7

switch

Answer 7

-sends data between computers on a LAN
-it uses the NIC address on a device to route traffic

Question 8

NIC (network interface card/controller)

Answer 8

hardware that connects a computer to a network

Question 9

transmission media

Answer 9

-physical media that can be used to transmit data
-e.g. twisted copper wire cable, fibre optic

Question 10

DNS (domain name system)

Answer 10

-the internet equivalent of the phone book
-maintains a directory of domain names and translates them to the internet protocol addresses

Question 11

Hosting

Answer 11

-websites are stored on dedicated servers
-used for websites that need to be available 24/7, be accessed by thousands of users at one time, be well protected from hackers and have an IP address that doesn’t change

Question 12

The cloud

Answer 12

-remote servers that store data to be accessed over the internet
-access anytime, anywhere from any device
-automatic backups
-collaborate files easily

Question 13

web server

Answer 13

-a program that uses HTTP to deliver web pages to users. Page requests are forwarded by a computer’s HTTP client
-dedicated computers and appliances may also be referred to as web servers

Question 14

client

Answer 14

a device that requests and/or uses services from a remote/connected server

Question 15

network topology

Answer 15

-the physical or logical arrangement of connected devices on a network
-e.g. computers, switches routers, printers servers

Question 16

star topology

Answer 16

-computers connected to a central switch
-if one computer fails, no others are affected. If the switch fails, all connections are affected

Question 17

mesh topology

Answer 17

-switches/routers connected so there is more than one route to the destination
-e.g. the internet. More resilient to faults but more cable is required

Question 18

wired connection

Answer 18

-any computer network that predominantly connects hardware via physical cables
- e.g. copper, fibre optic

Question 19

ethernet

Answer 19

-a standard for networking LAN using protocols. Frames are used to transmit data.
-a frame contains the source and destination addresses, the data and error-checking bits.
-uses twisted pair and fibre optic cables. A switch is used to connect computers

Question 20

wireless connection

Answer 20

-any computer network that predominantly connects hardware via Wi-Fi, eliminating much of the need for physical cabling

Question 21

Wi-Fi

Answer 21

wireless connection to a network.
-requires a wireless access point or router.
-data is sent on a specific frequency. Each frequency is called a channel

Question 22

Bluetooth

Answer 22

-a method of exchanging data wirelessly over short distances - much shorter than Wi-Fi

Question 23

encryption

Answer 23

-encoding readable data into unreadable data
-only the intended recipient can decode the data using a special key.
-protects sensitive communications against hacking

Question 24

IP address (internet protocol address)

Answer 24

-a unique as string of numbers separated by full stops.
-identifies each computer using IP to communicate via network

Question 25

MAC address (media access control address)

Answer 25

used as a unique identifier for most network technologies including Ethernet and Wi-Fi

Question 26

standards

Answer 26

-various rules for different areas of computing
-standards allow hardware and software from different manufacturers to interact with each other

Question 27

protocol

Answer 27

a set of rules that allow two devices to communicate

Question 28

TCP/IP (transmission control protocol/internet protocol

Answer 28

TCP provides error-free transmission between two routers. IP routes packets across a WAN

Question 29

HTTPS (hypertext transfer protocol)

Answer 29

-encryption and authentication for requesting and delivering HTML web pages.
-used in websites that are sending and/or receiving sensitive data

Question 30

FTP (file transfer protocol)

Answer 30

used for sending files between computers, usually on a WAN

Question 31

POP (post office protocol)

Answer 31

used by email clients to retrieve email from an email server

Question 32

IMAP (internet message access protocol)

Answer 32

used by email clients to manage remote mailboxes and retrieve email from a mail server

Question 33

SMTP (simple mail transfer protocol)

Answer 33

sends email to mail server

Question 34

protocol layering

Answer 34

the concept of protocol rules being built up in layers - the layered protocol stack facilitates the various rules being executed in defined order