ICT 141 Lecture 3: Introduction to Internet & Email

ICT 141 Computing Skills Fundamentals I

• Course: ICT 141
• Module: Computing Skills Fundamentals I
• Lecture: 3 - Introduction to Internet & Email

The Internet

• The Internet is a worldwide computer network connecting thousands of smaller networks.
• It links educational, commercial, non-profit, and military entities, plus individuals.
• It's a global networked system using TCP/IP to connect billions of devices globally.
• It is an international network of private, public, academic, business, and government networks, linked electronically, wirelessly, and optically.
• Also known as "The Net," "Info. Superhighway," and "Cyberspace."

Internet Penetration

• Image shows global network connections.

Who Owns the Internet?

• No single person or organization owns or controls the Internet fully.
• It's more of a concept than a physical entity.
• It relies on a physical infrastructure connecting networks to other networks.
• Its history starts with electronic computers developed in the 1950s.

How the Internet Works

• The Internet is a vast network linking thousands of smaller networks.
• Client/server networks are central to how it functions.
• A client is a computer requesting data or services.
• A server (host) is a central computer providing data or services.

Connecting to the Internet

• To connect, you need:
  • An access device (computer with modem).
  • A connection method (phone line, cable hookup, or wireless).
  • An Internet access provider.

Connecting to the Internet (Bandwidth)

• Bandwidth dictates connection speed.
• Bandwidth shows how much data a communications channel can send in a given time.
• Baseband connections are slow, allowing only one signal at a time.
• Broadband connections send multiple signals simultaneously, making them faster.

Data Transmission Speeds

• Data transfer is measured in bits per second (bps).
• 8 bits convey one character (e.g., 'A' or 'a').
• Kbps (kilobits per second) send 1,000 bits per second.
• Mbps (megabits per second) send 1 million bits per second.
• Gbps (gigabits per second) send 1 billion bits per second.
• Uploads send data from your computer to another computer.
• Downloads receive data from another computer to your computer.

Intranet vs. Extranet

• Intranets use Internet infrastructure for internal organizational use only.
• Extranets are similar to intranets, but they allow selected outside entities (e.g., suppliers) to access information.

Internet Services and Uses

• Email, discussion groups, research, news, entertainment, file downloads, e-commerce, financial services, online auctions, career advancement, e-business, and social networking.

World Wide Web (WWW)

• The web and internet are different.
• The web is multimedia-based and uses the internet's infrastructure.
• The WWW is an interconnected system of internet computers (servers) supporting multimedia documents.
• It's an information-sharing model built on the internet.
• It's a system of linked hypertext documents accessible through the internet.

Useful Concepts

• Hypertext: text with links to other text, allowing immediate access.
• Hyperlinks: references to data, followed by clicking or hovering.
• HTML (HyperText Markup Language): language for creating web documents.

Web Browser

• A software app for retrieving, presenting, and navigating information resources on the World Wide Web.
• Websites and information are identified by uniform resource locators (URLs).
• A URL can point to a webpage, image, video, or other content.

Web Browser (Model)

• Uses client-server model to function.
• Browser acts as the client, requesting information from web servers located on the Internet.
• Web servers process requests and send information back to the browser, which displays it on a device.

Examples of Web Browsers

• Popular browsers include Microsoft Internet Explorer, Mozilla Firefox, Google Chrome, Apple Safari, and Opera.
• Browsers can also access information on Intranets.

Mobile Browsers

• Often called microbrowsers, they are specifically designed for mobile devices.
• They are pared down versions of standard web browsers, optimized for mobile devices with limited memory and processing power.

Webpages vs. Websites

• Webpages are individual documents written in HTML.
• Websites are collections of webpages under a domain.
• Domain names help users access specific websites.

URLs

• Global addresses of documents or resources on the WWW.
• They consist of a protocol, host (domain), and location.
• Common protocols include http, ftp, and mailto.

Examples (URLs)

• URLs are provided as examples. Different protocols lead to different types and formats.

Static Webpages

• Displayed exactly as stored, with consistent content for all users.
• Typically created using HTML files.
• Do not require a web server for dynamic updates.
• Examples include a student's personal profile page.

Dynamic Webpages

• Content changes based on user interaction and specific criteria.
• Frequent updates (e.g., stock prices, weather).
• Created using client-side scripting (e.g., JavaScript) and/or server-side scripting (e.g., ASP, PHP, Hypertext Processors)

HyperText Transfer Protocol (HTTP)

• Protocol for viewing webpages on the WWW.
• Foundation for data communication on the web.

File Transfer Protocol (FTP)

• Network protocol for transferring computer files between hosts (e.g., between computers on the internet).
• Uses a client-server architecture.

Internet Security Protocols

• HTTPS (for secure web browsing) encrypts data in transit, protecting sensitive information.
• SSL/TLS (Secure Socket Layer/Transport Layer Security): protocols for secure communication.
• AES (Advanced Encryption Standard) is a powerful encryption algorithm.

Firewall

• A system for preventing unauthorized access to/from a private network.
• Firewalls regulate messages entering and leaving an intranet, ensuring they meet security criteria.

Search Engines

• Websites or systems designed to search the WWW for information.
• They commonly present results as a list of search results pages.
• Google, Yahoo, Bing, etc. are examples of search engines.

Email Services

• Electronic mail (email or e-mail) is a common method of sending electronic messages.
• Ray Tomlinson sent the first email in 1971.

Email Addresses

• Provide an example list of email addresses (e.g., Gmail.com, Yahoo.com, etc).

Composing an Email

• Instructions on using "TO," "CC," and "BCC" fields. Identifying messages for recipients (e.g., cc)

Email Parts

• Graphical explanation of email formatting components: send, reply, subject, etc.

Email Attachments

• Documents (often in different file types) attached to email messages.
• Recipients need appropriate software to open such attachments.
• Attached files may contain security risks.

Challenges of Using the Internet

• Privacy, security concerns, lack of central governing body, and existence of unauthorized websites.