UNIT4. NETWORK AND INTERNET

In this unit you will find out the answers to this questions: What isa computer network?, How would you describe the Internet?, What are the elements ofr an Internet address? How you can search for information on the Internet? What are the advantages and disagvantages of communication between computers?. 
Theory and questions in this link: NETWORK


ACTIVITIES OF THE LINK

Questions (I)


1. What is a computer network? Which is the simplest network?
Computers are network when they are conected to each other and can exchange information. The simpliest example of a computer network is that of two computers connected directly through a network cable.

2. How can a small computer network be created?
By conecting various computers to a device called a switch. There are switches for 4,8,10,12,16,24 or more computers.

3. What does the star network configuration consist of? What advantage does it offer?
It consists on many devices conecting by a cable to the switch. The advantage is that if a cable of a computer breaks, the problem only affect to that computer.

4. What is the purpose of a switch?
Direct the traffic of information between the devices.

5.  What is the most commonly used technology in small networks?
Ethernet technology.

6. What is the purpose of a network card? Where is it installed?
The purpose is to connect the computer to the network, it acts as an intermediate. It is installed in the external slots of the motherboards of the computers.

7. A network card does not have to be installed in desktop computers or the more modern laptops. Why?
Because this computers have been made with the network card installed.

8. What is a network card controller?
The card that controll the computer and without it, it will just be a pair of chips and cables.

9. What is a network protocol? Which is the most commonly used?
A network protocol is a program of the computer that consists on norms or rules showing the methods of how to recieve or send information with networks. The most common are IP or TCP.

Questions (II)

1. What is the purpose of a computer network?
Search information between two or more devices.

2. What is a shared folder? List 3 cases in which a shared folder is used.
A shared folder is a folder which you determinate that has to be shared by other devices. One case: you make a folder with photos. Other: internet. Other: a folder with shared music.

3. What is a server? What is a client?
A server is the computer that supplies the service.
The client is the one who recieves that service.

4. Give two examples of shared hardware on a network.
ADSL router. Printer.

5. What does sharing a netwoked programme mean and what are the advantages?
It means that only a computer has to download a programme and the others can use it. the advantages is that it proporcionates a better use of the software and facillizates the collaborative work.

6. What is a networked database? Advantages? When is it used?
When some devices are working on a collaborative work. The advantages are that programs are installed on a single computer. It is used when a lt of computers are working at once.

7. What is a specialized server?
The computer that requiers better components and higher quality parts because it is the server.

Questions (III)

1. How can we connect a network to the internet?
By connecting the network to a router and the router to a telephone line.

2. What do routers do? The most common?
Routers lead the connection. They have a switch to connect to the telepone line and others to connect to the devices. The most common are ADSL routers.

3. What are the characteristics of routers that are used in homes and small offices?
That they have the switch inside them.

4. How can we tell if a router is a WiFi router?
Because WiFi routers have antennas and places to connect the devices' cables and the telephone line's cable.

5. What does a computer need to connect to a wifi network?
If is a desktop computer, it needs a cable to connect to the router. But if is a movible device (like a PDA) is just need the wireless.

6. What advantages does a WiFi connection offer? Do you know any disadvantages?
That it is easier to manage and more devices are able to connect to it. Disadvantages: Maybe the service fails.

Questions (IV)

1. What is a LAN? What does "LAN" stand for?
It means Local Area Network. It stands for some computers in the same building (a house, a small shop)

2. What is a WLAN?
Wireless Local Area Network, it is the network program used for some devices just for internet.

3. Two examples of LAN.
Internet and a shared folder.

4. What is a Metropolitan Area Network?
MAN is a network used for computers in the same city or municipality.

5. Explain a case where a MAN would be useful.
In a company all over a city, for employers that need the same network.

6. What is a Wide Area Network?
A WAN is the network used in a country or a continent or even the whole world.

7. The internet is an example of WAN. Why?
Because it's a network used by millions of computers all over the world.

8. Give an example of WAN (not internet)
Microsoft Word.

9. Draw an small diagram showing three types of networks and the means of information transmission each one of them uses most.

4.1. COMMUNICATION SYSTEM 

When you communicate with anther person you use a communication system where are the following elements: interlocutors, the messages, the means and the code. 
In ICT (Information and Communication Technology) you use a computer as a means, the users as the interlocutors, the files are the messages and the protocols as the type of codes that the computers use to understand each other.
A network is two or more computers connect to one another tha can share documents, files, printers, etc. Some networks have a powerful computer called a server which manages the network and stores most of the information. As well as there are terminals, which are less powerful computers that work with information received from the server.
A server basically consists of the following elements: the server, the terminals, a network card for each computer to transmit and to receive the data, a transmission means, a switch tha controlls and distributes the data the computers and the neccesary programs to transmit this information from one computer to another.

ACTIVITY 1.

a) Copy and complete the table in your blog about these means of communication:

	INTERLOCUTORS	MEANS	CODE
TELEGRAPH		Electric cable
FAX			Sounds
SMOKE SIGNAL
POST OFFICE
TELEPHON
TELEVISION

b) Do you know Morse code? The most famous message is SOS  ***---***. Transmit a message to your partner in morse touching his back quickly for the dots and longer for the dashes. Look at the code on the internet and copy it into your blog. Write down your name with this code.
.... . .-.. .-.. ---  ->  hello

4.2. INTERNET. THE NETWORK OF NETWORKS.
The Internet is a huge network of networks, interconected worldwide.
When we go into the Internet we connect our computer to a server. There are millions of servers all over the world each of them identified bya a domain name (eg. www.terra.es). The generic top-level domains consist of two or three letters is used to indicate the locations, organisation or field tha this website belons to (e.g. es,org, com, net, edu, ...)
INTERNET SERVICES: 
A) WEB PAGES:  these are enriched text documents with many format options. The are divided into frames and can include images and other multimedia elements, eg. sound or video files. Web pages include links to different parts. These web pages have the extension HTML and it is necesary a browser to be readed. 
B) BLOGS AND WIKI PAGES: Blogs and wiki pages are special types of web pages. Blogs contain articles from one or several authors. The most recent entry appears first on the page. Wiki pages can be created and modifield by different users from their browser. Any can participate in creating and editing the information (eg. Wikipedia).
C) E_MAIL (ELECTRONIC MAIL): enables us to send and receive messages that contain either text alone to text multimedia elements.There are two types of email: POP or WEB Email.
D) SOCIAL NETWORK. A virtual communicaty is a group of people who communicate and have relationship in a virtual space: tuenti, facebook, myspace, orkut, etc. 
E) OTHERS: Chats, Forums, P2P networks, FTP, IP Telephony, Instant messaging.

ACTIVITIES Nº1.

1.- Find out about these programs: PIDGIN, OPERA, EUDORA, ARES, COFFECUP, AMAYA, PEGASUS MAIL, BITTORRENT.What Internet service are the desingned for?
2.- Using Google Docs or Hotmail Docs, work with a classmate and create a glossary of terms related to computers security that includes entries such as: virus, antivirus, firewall, compunter worm, trojan, malware, hoax, etc. ..share this file with its link and put it into your WebBlog.

TASK 1.

1.- Go to the home page of Nominalia  www.nominalia.com  and find a form wher you can check if a domain name is registered or not. Try with different names and compares your findings with the rest of the class.  
2.- Create a simple web page using HTML programing: LINK: Códido HTML 
3.- Create a web page using for example www.everyoneweb.es (or http://sites.google.com) that offers the opportunity of creating a web page direcly on the web site, working from the browser and without installing any programs on your computer. 

TASK 2.

1.- Create a wiki.

ANEXES:

http://www.webs.com/
http://galeon.hispavista.com/
http://www.everyoneweb.es/
http://www.uv.es/jac/guia/  (Guía Código HTML)