1) A router is a hardware device which takes and analyzes data, then directs them to the appropriate location.
2)WiFi is a enabled device (in phones,laptops, iTouch etc) which can connect to the internet via a wireless network, you can create a Hotspot to allow one or more devices to connect to the internet wireless. Bluetooth use in a network is to allow users to exchange data, it's useful because it overcomes any synchronization problems.
3)Internet is a global system connected by various computer networks (not as secure as Intranet). Intranet is practically the same but used in huge firms (I.e Microsoft) to securely transfer information, whether they are in the USA and have to send volatile information to a sub-firm in Asia.
4)Not sure about the small network thing but I think you are talking about needing the use of dial up. You have to have a dial up, internet browser such as Google Chrome (anything that can access the WorldWideWeb). Yo also need access to a Internet Service Provider. All this comes when you buy a computer. Not sure if I answered this part.
5) Medicine expert systems, Car engine fault expert systems and Agriculture expert system.
Hope this helped
