Internet technologies

• Internet is a global system of interconnected computer networks.
• Vinton Gray Cerf is considered the father of the Internet.
• Tim Berners Lee proposed the idea of the World Wide Web (WWW).
• Intranet is a private computer network, similar to the Internet, using TCP/IP protocol for sharing within an organization.

Hardware and Software for Internet Connection

• Computer with Network Interface Card (wired/wireless) and TCP/IP compatible OS
• Modem
• Internet account from an Internet Service Provider (ISP)
• Software like browser, email client, chat applications

Dial-up vs. Wired Broadband

• Dial-up offers slow connection speeds (up to 56 kbps), requires dialing, uses telephone line exclusively, uses dial-up modem
• Wired broadband offers high-speed connections (usually > 256 kbps), is always on, allows simultaneous voice and Internet, uses a broadband modem

Broadband Technologies

• Integrated Services Digital Network (ISDN) is a broadband service for voice and digital data.

• Cable Internet: Internet access via coaxial cables used for TV signal transmission.

• DSL: Internet connection through standard telephone lines.

• Leased lines are dedicated lines for Internet to ISPs, businesses, etc.

• Fibre to the Home (FTTH) uses optical fibres for data transmission to homes.

• Wireless broadband provides speeds similar to wired, including Mobile Broadband, Wi-MAX, Satellite Broadband, and Wi-Fi.

• Mobile broadband: Wireless Internet via mobile phone, USB modem, tablets, etc.

• Wi-MAX (Worldwide Interoperability for Microwave Access) offers wireless Internet up to 50 km.

• Satellite broadband provides Internet connectivity through a satellite.

• Internet connection sharing allows multiple computers to use one connection via LAN, Wi-Fi, or Li-Fi.

• Internet services: WWW, e-mail, search engines, social media, etc.

• World Wide Web (WWW) is a system of interlinked hypertext documents accessed via the Internet.

Web Browsers

• Web browser software retrieves, presents, and navigates web pages (e.g., Chrome, Explorer, Firefox, Opera, Safari).

Web Browsing Procedure

• Browser requests IP address from ISP's DNS

• Server returns IP address

• Browser makes a TCP connection to the server

• Browser sends a GET request for the file

• The server returns the file

• Search engines: Websites designed to help find information, using web crawlers (spiders/robots).

• Search engine functioning: Web crawlers find keywords on web pages and store them with URLs, creating an index, then displaying a list of URLs when a topic is searched.

• Email is digital message exchange over the Internet.

• Email sections: "To" (recipient), "Cc" (secondary), "Bcc" (tertiary), Subject, Content, Attachments.

Email Functioning

• Sender composes message using email client/webmail
• Sender uploads message to SMTP (Simple Mail Transfer Protocol) server
• Message traverses the Internet
• Message arrives at receiving server and is placed in recipient's mailbox
• Recipient's email checks for new messages and downloads it
• Recipient reads the message

Email Advantages

• Email's advantages include speed, ease of use attachments, environmentally friendly, easy reply and cost effectiveness

Types of Social Media

• Social media types are internet forums, social blogs, micro blogs, wikis, social networks and content communities
• Internet forums are for online discussions via posted messages (e.g., Ubuntu Forum).
• Social blogs are informational websites with reverse chronological posts (e.g., Blogger, WordPress).
• Microblogs allow short sentences/images/videos exchange (e.g., Twitter).
• Wikis enable users to add/edit content for collaborative documents (e.g., Wikipedia).
• Social networks allow personal web pages and connecting with friends (e.g., Facebook, LinkedIn).
• Content communities organize and share content like photos, videos, etc. (e.g., YouTube, Flickr).
• Advantages of Social media: brings people together, plans and organizes events, business promotion and enhances business skills
• Limitation of social media includes intrusion to provacy, addiction and spreading rumours

Malware

• Computer virus attaches itself to other programs, spreading without knowledge and interfering with computer operations.
• Computer worm is standalone malware that replicates to spread to other computers.
• Trojan horse appears useful but damages once installed/run.
• Spams: Unsolicited emails sent to promote a product or service.
• Hacking is manipulating network connections.

Ethical Hacking

• Ethical hacking performed by "white hats" to test and secure vulnerabilities
• Criminal hacking ("black hats") breaks into networks to destroy data
• "Grey hat hackers" act illegally to identify vulnerabilities

Network Attacks

• Denial of Service (DoS) attacks a web server, forcing a restart.
• Phishing attempts to acquire information by impersonating original websites and creating misleading websites (spoofing).
• Man-in-the-middle attack secretly intercepts and modifies messages; use HTTPS/SFTP for secure transactions.
• Firewall provides network security, denying malicious data.
• Antivirus programs detect, cure and remove viruses by scanning known viruses.
• Cookies are small text files websites create that remember usernames, preferences, etc, that can be used as spyware.
• Mobile computing is computing and data transmission while in motion, using devices like laptops, tablets, and smartphones.
• 1G mobile phones were analog with basic voice.

Generations of Communication

• 2G networks were digital , introducing picture messages and MMS.
• 3G networks offered multimedia combining voice and data.
• 4G (LTE) provides ultra-broadband Internet access with high speeds and quality images/videos.
• Mobile communication technologies include SMS, MMS, GPS, and smart cards.
• SMS is a text messaging service (up to 160 characters).
• MMS sends multimedia content.

GPS

• GPS is a satellite navigation system for locating positions.
• Smart cards store/transact data.
• Advantages of using Secure, intelligent and convenient smart cards.
• Mobile Operating System manages hardware, multimedia, Internet (e.g., Android, iOS, BlackBerry OS, Windows Phone).
• Android (Linux-based) is for touch screen devices, developed by Android Inc. (founded by Andy Rubin in 2003) and acquired by Google in 2005.

Explore Internet characteristics, broadband technologies, and security. Identify components for connecting to the Internet and security measures.