Communications & Networks Standard Grade Revision: Networks

What is a Network? A series of computers linked together so can send and receive data. We use them for sending s, downloading files, shopping, etc They are divided into two types: –Local Area Network (LAN) –Wide Area Network (WAN)

Local Area Network (LAN) Cover a small area such as one room or building. –The school has a LAN Each computer on a LAN is called a station One station is called the file server. –The file server is where all the data & files are kept

Advantages of a LAN Share data Share peripherals (resource sharing) Passwords keep data secure Different levels of access –stop unauthorised access Flexible access –Use any station connected to the LAN Many users can use same document at the same time (workgroup computing)

Transmission media for LAN Stations can be connected by cables or wireless technology Cables: –Unshielded Twisted Pair of copper wire (UTP) Uses electrical signals to transmit data Cheaper but can get interference –Optical fibre Uses light beams to transmit data Expensive but doesn't get interference

Transmission media for LAN Wireless –Infrared communication Like the TV controls –Bluetooth Range of about 10 metres –WIFI ( Wireless Fidelity Alliance) Range of about metres Bluetooth & WIFI use radio waves

Wide Area Networks (WAN) Connect computers across large distances Spread across countries & cities worldwide using telecommunications links Similar advantages to LAN but on a bigger scale.

Transmission Media for WANs Telecommunications links –The communication of information over a distance using: Microwave transmission Satellite links Optical Fibre

Network Security Security methods include: –Passwords –Encryption –Physical methods

Correct - Click anywhere to continue Incorrect - Click anywhere to continue You answered this correctly! Your answer: The correct answer is: You did not answer this question completely You must answer the question before continuing SubmitClear LAN stands for Local Active network A) True B) False

You answered this correctly! Your answer: The correct answer is: You did not answer this question completely SubmitClear Complete the sentence below by filling in the blanks. each other. WANs are computers LANs are computers linked each other.

Correct - Click anywhere to continue Incorrect - Click anywhere to continue You answered this correctly! Your answer: The correct answer is: You did not answer this question completely You must answer the question before continuing SubmitClear Out of the phrases below, the two which give the best advantages of a LAN are (type exactly the words between the commas only, not the commas): look nicer, share data, share cables, save time, easy to set up, use less electricity, communication

Correct - Click anywhere to continue Incorrect - Click anywhere to continue You answered this correctly! Your answer: The correct answer is: You did not answer this question completely You must answer the question before continuing SubmitClear Another word for a station is a 'client'. A) True B) False

Correct - Click anywhere to continue Incorrect - Click anywhere to continue You answered this correctly! Your answer: The correct answer is: You did not answer this question completely You must answer the question before continuing SubmitClear A 'server' computer on a network got its name because the person who invented it was a butler by profession. A) True B) False

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