Tema 2 Internet - La Red De Redes PDF

## Internet, the network of networks ### What you will learn in this unit: - What a computer network is. - How to access the internet. - How to browse securely. - How to install programs in Guadalinex. - How to copy, cut and paste files using both the mouse and the keyboard. ### The birth of the...

## Internet, the network of networks ### What you will learn in this unit: - What a computer network is. - How to access the internet. - How to browse securely. - How to install programs in Guadalinex. - How to copy, cut and paste files using both the mouse and the keyboard. ### The birth of the internet At the end of the 1960s, the Advanced Research Projects Agency of the US Department of Defence (ARPA, for its acronym in English) commissioned several universities and private companies to create a communications system capable of delivering information to its destination, even if part of the system were destroyed. This is how the first network of interconnected computers was born. This network, called ARPANET, grew and became more open and popular. More computers and computer networks connected to it, until it reached over 4,000 million users today, who use the internet worldwide. ### The beginning The first connection of computers within the ARPANET project took place on October 29, 1969. Many believe this event marks the birth of the internet. ### Online Research The development of the internet was a long and complex process involving many people. History acknowledges some of them as the true "fathers of the internet" for their important contributions. Research to answer these questions: - What four people are considered the fathers of the internet? Write a short biography about each of them: where they were born, what they studied, where they worked... - What were their contributions to the development of the network? Explain what changes and advances the internet experienced thanks to the intervention of these people. ### The time to talk - Why do you think it might be useful to connect several computers together to form a network? - What tasks can we do when we are connected to the internet that we can't do when we are not? - Do you know any website on the internet where you can find online games appropriate for your age? - Do you think it is necessary to protect your computer before you start browsing the internet? ### Computer Networks Computers are getting more powerful every day and can perform very complex tasks at incredible speeds. However, sometimes we need to connect several computers together so they can work together. For example, you might want several computers connected to share data or programs between them. A computer network is a set of interconnected computers and software designed to share information and resources. The internet is a giant network of interconnected computers. People who have access to it can take advantage of the countless resources that millions of users connected to this network share. ### Accessing the internet Today we have a wide variety of possibilities to connect to the internet. Desktop computers and laptops connect through a traditional telephone line, fiber optic cable or satellite, while mobile devices connect thanks to 3G, 4G or 5G wireless networks. Each connection system has its own advantages and limitations. ### Internet Connection Systems - **ADSL, fiber optic, satellite, 3G, 4G**: transmit information through cables. - **Satellite, 3G, 4G, 5G**: do not require cables. | System | Speed | Coverage | Price | Stability | Power Consumed | |:-----:|:-----:|:-------:|:-----:|:-------:|:---------------:| | ADSL | High | Wide | Medium | High | Low | | Fiber Optic | Very High | Limited | High | Very High | High | | Satellite | Acceptable | Maximum | Very High | Very Low | High | | 3G | Low | Medium | Low | Low | Low | | 4G | High | Limited | Medium | Low | High | ### Browsers Once we are connected to the internet, we need to use programs that allow us to browse the network, that is, access the many resources we have available. These programs are called browsers. The best-known are Edge, Internet Explorer, Mozilla Firefox, Google Chrome, Safari and Opera. Of these, Internet Explorer and Edge work only with Windows, and Safari mainly with Mac OS X. The other three browsers have versions that run on all operating systems. ### Search engines When we don't know the address or URL of an internet service, we can find it using search engines. They are divided into three main types: - **Search engines**, like Google or Bing. They search the network automatically, making the results less precise, yet very extensive. - **Directories or thematic indexes**, like Yahoo!, Dmoz or Galaxy. They consist of directories with websites arranged by topic and categories manually registered. These results tend to be more precise but also more limited. - **Metasearch engines**, like Dogpile or Ixquick. They find information in the most commonly used search engines and show a combination of the results obtained from each of them. ### Browsing the internet The internet offers a wide variety of services and utilities. The most used service is the World Wide Web (WWW), also known as "the web." It is a system containing a special type of documents called hypertext documents, better known as web pages. These documents can include links, meaning connections that lead to other documents or web pages. In many cases, several web pages are combined to form a website, which usually has a landing page from which all other pages on the website can be accessed. This landing page has an address or URL, which we can find in a search engine if we cannot remember it. ### A tour of the WWW In 2019, there were about two billion websites. They constantly and increasingly grow, as can be seen at Internet Live Stats, where data regarding the size of the WWW is updated in real time. Within this immense digital web, we can find pages and sites dedicated to almost any topic. For example, we can find: - **Educational sites**: Modern browsers can display interactive content where we can act by typing, touching, moving objects... This feature of the network facilitates learning, since we can experience for ourselves the content that is studied on each site. Two sites where you can find this type of content are Portaleducativo and Educaplus. - **Music**: There are many websites on the internet where you can legally listen to music. Some of the best-known are Deezer and Spotify. To take full advantage of these services, you need the device you are using to have built-in speakers or to connect it to some external speakers or headphones. - **Videos**: Thanks to improved connections, which have allowed for faster data transmission from the network to our devices, it is currently possible to watch videos in streaming, meaning without having to download them first. Two of the main reference sites are YouTube and Vimeo, besides streaming platforms like Netflix, Amazon Prime Video and HBO, which are constantly growing in popularity. - **Magazines**: There are websites hosting magazines specialized in youth content, like Bravoporti. If you are interested in a particular topic, you can search for magazines about it on Issuu or Calameo and consult them for free. - **Forums**: These are open websites where opinions and online debate are encouraged. They tend to be organized by topics or categories. New discussion topics can be opened so other users can share their opinions. You can often find people in forums with a lot of knowledge about certain topics who are willing to share their knowledge with those interested. - **Schoolwork**: There are also websites that help us to present schoolwork in a different or original way. One such website is Classtools, which includes tools for completing assignments, like Fakebook and SMS Generator. Another interesting website is Prezi, which allows you to create presentations online, or Google Presentations, where the same document can be edited by several users collaboratively. ### The internet’s downsides New technologies also come with disadvantages. To keep the internet running, many computers need to run continuously. To produce the electricity that they consume, a lot of fossil fuels are burned, which produce 2% of global CO2 emissions. ### Security on the network When we go online, we connect to a huge network of computers that share information with us. We are also opening a door for other computers to access ours. This has resulted in people who are experts in using TICs designing malicious programs or malware, to damage other people's computers or obtain the information stored in them. **Warning:** accessing this site may damage your computer. **Suggestions:** * Go back to the previous page and choose another result. * Do another search to find what you are looking for. * If you want, you can access [link] under your own responsibility. To get detailed information about the problems we detected, visit the "Safe Browsing" diagnostic page on this site. * To learn more about malware on the internet and how to protect yourself, visit the StopBadware.org website. * If you are the owner of this website, you can request a review of it through Google’s Webmaster Tools. You can find further information regarding the review process at the Webmaster Help Center. * Advice provided by Google. ### Types of malware - **Virus**: are programs designed to infect files. They can cause annoying or destructive effects on the systems they infect. The creators of these programs don't receive any benefit from them. As a result, their number has decreased over the last few years - **Trojan horses**: these are malicious programs disguised as something appealing, yet they hide software that gives a malicious user access to the infected computer. - **Adware**: these programs display unsolicited ads by the user, which are often annoying and difficult to delete. Sometimes, they are installed when we agree to the terms of use of free programs downloaded from non-official websites, without realising we are accepting them. - **Spyware**: their mission is to collect information about user activities and distribute it to advertising agencies, companies or organisations interested in this data. - **Hijackers**: these programs modify browser settings. For example, some change the homepage to advertisements, while others redirect search engine results to ads or paid pages. ### Malware Malware is a kind of software that aims to infiltrate or damage a computer without the owner's consent. This term encompasses many kinds of malicious programs: virus, trojans, spyware, adware, etc. ### How to protect against malware As we have seen, our computers are exposed to many risks when connected to the internet. To protect them and the information they contain, we must take some measures: - Back up important files. - Install antivirus, anti-trojan and anti-spyware programs. Free versions of all these programs exist. - Download and install programs from their official website, and not from a free software website. - Always keep the firewall (firewall) of the operating system active. This application protects the computer from external intrusions. - Always keep your operating system updated to the latest version. - Never reveal your passwords to anyone. - Never open attached files sent by email or instant messaging if you didn't expect them. Even if they come from a known contact, ask before opening them. - Always pay attention to how the device is working. If you notice suspicious behavior, check with an adult. Abnormal slowness, the webcam turning on by itself or strange noises are signs that shouldn't be overlooked. ### Firewall A program or security software that blocks access to a computer, protecting it from unwanted connections. ### Activities 1. Consult the table on page 18 and answer: - What type of internet connection would you consider most appropriate if you lived in a big city? What about if you lived in a remote house in the countryside? 2. Have you ever been affected by some type of malware on your electronic devices? - What were the symptoms it displayed? - How did you solve the problem? - Discuss in groups and share your conclusions. ### Basic Actions: copy, cut, and paste The most frequent operations done with files in any operating system are three: copy, cut and paste. When copying, we make a copy of the selected files or folders, which we can then paste somewhere else, without the original files disappearing. However, when cutting, we delete the files from their original location, and they can be pasted elsewhere. 1. **To copy**: Select the files or folders and right-click any of them. In the menu that appears, click "Copy." You can also do this by pressing the Ctrl and C keys simultaneously. 2. **To paste**: Right-click anywhere in an open folder and select "Paste" from the menu that appears. You can also do this by pressing Ctrl and V simultaneously. 3. **To cut**: select the files or folders, then right-click any of them, and in the context menu that appears, select "Cut." You can also press Ctrl and X keys simultaneously. If you choose the cut option, the files disappear from their initial folder, but they remain available to paste them elsewhere. ### Installing programs in Guadalinex It is possible that you may need to use some programs that are not installed in Guadalinex. This is not a problem, as this operating system makes it very easy to install programs. It searches for the program and installs it on your computer. For example, we are going to install the GIMP image editor, which we will need later in the course. 1. In the Guadalinex application menu, click on “System Tools.” A directory will open where you must select “Guadalinex Edu Software Center.” 2. In the search box with a magnifying glass, type the name of the program you want to install. As you can see in the image, the software center locates the program. Click on “Install.” 3. A window will open with the characteristics of the program you want to install. You will see a highlighted blue button that says "Install." Click on this button. The system will take care of the rest. 4. The installation process will finish and the new program will be available in the Guadalinex application menu. In our case, it is in the Graphics section.