Unit 1.4 - Wired And Wireless Networks Flashcards Preview

OCR GCSE 2019 COMPUTER SCIENCE > Unit 1.4 - Wired And Wireless Networks > Flashcards

Flashcards in Unit 1.4 - Wired And Wireless Networks Deck (32)
Loading flashcards...
1

Stand-Alone Pc

Computer that is
not connected
to any other device, network or the internet.

2

A Network

Two or More Computers connected together

3

Advantages of - Network

- Share Hardware (Printers) - - Share Files
- Log on anywhere
- Central Backups
- Central Virus checks

4

Disadvantages of - Network

- Viruses & Hackers
- Network Failure & Traffic
- Costs of Hardware &
Software needed
- Expert Knowledge & Skills
needed

5

LAN

Local Area Network

Small geographical location

6

WAN

Wide Area Network

Large geographical location (Network of Networks)

7

A Switch

Links Computers and Peripherals in an LAN

Switch - Sends data only to device needed

8

A Hub

Links Computers and Peripherals in an LAN

Sends data to all devices

More Data Collisions, Slower Network, Cheaper, Security Risks

9

Network Interface Card (NIC)

Needed in Every Device / Peripheral to connect to a Network

MAC Address

10

Router

Receives, Forwards, Directs
data packets between Networks & Computer

11

Wireless Access Point

Links computers & peripherals Wirelessly

12

Modem

Modulator Demodulator

Converts analogue signals to digital and back again

13

Bridge

Connects two separate LAN Networks.

Relays data to receiving computer.

14

Server

Responds to request for data

Stores data used by other computers on a network

15

Ethernet

Twisted Pairs of Cables

Cat-5, Cat-5e, Cat-6

Cheap, Sturdy
Short Distance (100m) & EMI/RFI Interference, Slower

16

Coaxial Cable

Insulated Central Wire

Braided wire shield to Prevent Interference

Cheap, Long Distances
EMI/RFI Interference

17

Fibre Optics

Glass Threads
Transmit Light as Data

Fast Bandwidth (10 Ghz), Secure,
Long Distance, No Interference
Expensive, Brittle

18

Client-Server Network

Client makes requests to the server for Data, Access & Programs.

19

Peer-to-Peer Network

All Computers are Equal

Peers download/share different parts of the same file.

20

Network/Wired Performance

Transmission Used (Fibre or Copper)

Number of Users

Bandwidth

Error Rate

Latency

21

Wireless Performance

Frequency Range

Channels Used / Sharing Channels

Distance from WAP

Physical Obstacles (Thick Walls, Metal)

Non-Wifi Interference (Microwaves, Cordless Phones)

22

Bandwidth

How much data can be transferred over a connection in a given time

23

Latency

How much Delay in sending and receiving bits.

24

Error Rate

How many data errors happen over a given time.

Sending a 0 instead of 1
Caused by Weak signals over longer distances
Or Electromagnetic / Radio Frequency Interference

25

The Internet

World wide collection of computer networks

26

DNS

A directory to match the URL (Domain Name)
with their IP address

27

Hosting

Websites stored on Dedicated Web Servers

28

The Cloud

Remote Web Servers used to store data and software accessed using a device on the internet.

29

The Cloud - Advantages

Cost - Less Hardware

Cost - Less Technical staff

Automatic Backup

Access Anywhere, Anytime

Any Device, Any OS

Software auto updated

Easy Collaboration

30

The Cloud - Disadvantages

Reliant to keep data Safe

Need Internet

Hackers & Attacks

Servers fail - No data

Business fails – data is lost