Internet Fundamentals/Introduction

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The Internet[edit]

What is the Internet?[edit]

  • The Internet is a global Wide Area Network (WAN).
    • A Network is a group of interconnected devices.
    • A Wide Area Network (WAN) is a network that covers a large area.
    • A Local Area Network (LAN) is a network that covers a small area.

What are the main advantages of the Internet?[edit]

  • Communication : Electronic mail (Email) and social media.
  • Education : search engines and webpages.
  • Entertainment : online games and online media.
  • Online services : online shopping and online banking.

What are the main disadvantages of the Internet?[edit]

  • Threat to personal information : possible loss of name, address, credit card number,...
  • Spamming : unwanted Emails that serve no purpose.
  • Cybercrime : malware, ransomware, stealing of identities,...
  • Virus attacks : cause a system to crash and may delete important data.

History of the Internet[edit]

  • In the 1950s, the United States Defense Department formed the Advanced Research Projects Agency (ARPA) with the purpose of developing technology.
  • ARPA’s scientists could not easily communicate or share information, so they created a network of computers, which they called ARPAnet.
  • In the 1970s, the TCP/IP protocol was developed, this protocol allowed the separate networks to communicate with each other.
  • The joining of these networks created a huge WAN which came to be known as the Internet.

The World Wide Web (WWW)[edit]

What is the World Wide Web (WWW)?[edit]

  • The World Wide Web (WWW) is a collection of different websites that can be accessed through a web browser.
    • A website is a group of web pages hosted on one web server.
    • A web server is an Internet server that serves web pages to the web browser.
    • A web browser is an application that displays web pages.

What is the difference between the World Wide Web (WWW) and the Internet?[edit]

  • The Internet is a global WAN, and the WWW is an Internet service.

How the World Wide Web (WWW) works?[edit]

  • When a user makes a request over the Internet, the web browser sends this request to a web server, and the web server accepts and responds to it by storing and transferring web pages to the web browser.

How are web pages transferred from servers to clients?[edit]

  • Any resource connected to the WWW is identified by its Uniform Resource Locator (URL).
    • A Uniform Resource Locator (URL) is the address of a WWW page.
    • Example : http://www.example.com/...
  • When the URL of a web page is identified, a protocol called Hyper Text Transfer Protocol (HTTP) sends a command to the web server.
    • Hyper Text Transfer Protocol (HTTP) is a protocol which enables communication between web clients and web servers.
  • Once the web server has transmitted the requested page, the web page can be displayed with Hyper Text Markup Language (HTML).
    • Hypertext Markup Language (HTML) is the standard language for creating and displaying web pages.

History of the World Wide Web (WWW)[edit]

  • In 1990, the WWW was invented by Tim Berners-Lee.
  • He created three technologies (HTML, URL and HTTP), which allowed to use the Internet to link one document directly to another.


Internet connectivity[edit]

What is needed to connect to the Internet?[edit]

  • Internet Service Provider (ISP) : a business that provides a connection to the Internet.
  • Modem : a piece of hardware that allows a device to connect to the Internet over a telephone line.
  • Router : a piece of hardware that allows several devices to connect to a single Internet connection.

Common methods of Internet connection[edit]

  • Dial-up : an Internet connection which uses a telephone line and requires a landline.
  • Digital Subscriber Line (DSL) : an Internet connection which uses a telephone line, but doesn’t require a landline.
  • Cable TV : a wired Internet connection which uses Cable TV lines.
  • Wi-Fi : a wireless Internet connection which uses radio waves.
  • Satellite : a wireless Internet connection which uses satellites orbiting the Earth.
  • 3G and 4G : wireless Internet connections which use cellular networks.

Cloud computing[edit]

What is cloud computing?[edit]

  • Cloud computing is the process of storing and using services online, rather than storing them locally on a device.

What are the main advantages of cloud computing?[edit]

  • File storage : access files, documents and Emails from any device.
  • File sharing : share files with several people at the same time.
  • Backing up : protect your files.

What are the main disadvantages of cloud computing?[edit]

  • Copyright : possible loss of legal rights.
  • Security : vulnerability to security attacks.
  • Storage : limited storage.