Notes on Internet and World Wide Web

Overview of the Internet

  • Definition: The Internet is a worldwide network of computers that connects various devices and allows for communication and data exchange.

  • Internet Service Providers (ISPs): Organizations that provide Internet access to homes, schools, and businesses. Each country has its own local ISPs. Local ISPs connect with others to establish a global network.

    • Popular ISPs in the Philippines: PLDT, Smart, Globe, SKY, CONVERGE, and PURE FIBER TECHNOLOGY (broadband).

History of the Internet

  • Origins: The Internet originated from the Advanced Research Projects Agency's Wide Area Network (ARPANET) in the 1960s, initially established for military collaboration.

  • Expansion: ARPANET grew as other universities and institutions connected, leading to the term "Internet" becoming widely used.

  • World Wide Web (WWW): The advent of hypertext-based technologies provided avenues for text, graphics, and multimedia, enhancing Internet growth significantly.

The Internet Today

  • User Statistics (As of October 2024): 5.52 billion Internet users globally (68% of the population), 86.98 million in the Philippines (73.6%).

  • Characteristics:

    • No ownership or centralized control.

    • Open accessibility.

  • Standard Organizations:

    • Internet Society (ISOC): Founded in 1992, promotes global Internet development and accessibility.

    • Headquarters: Reston, Virginia and Geneva, Switzerland.

    • World Wide Web Consortium (W3C): Founded in 1994 by Tim Berners-Lee, responsible for web standards and protocols.

    • Operates through major institutions including MIT, ERCIM, Keio University, and Beihang University.

Data Transmission on the Internet

  • How Data Moves:

    • Data from applications is broken into packets.

    • Packets are sent through various network devices: routers, ISPs, and modems.

    • Packet switching vs. circuit switching:

    • Packet Switching: Breaks data into packets, enabling efficient bandwidth usage.

    • Circuit Switching: Dedicated channel, inefficient for continuous use.

  • Advantages and Disadvantages:

    • Circuit Switching: Dedicated but inefficient due to waiting time.

    • Packet Switching: Efficient but packets may be lost and require reassembly.

Functionality of Computers on the Internet

  • Servers: Store data, run software, have various roles, examples include:

    • Active Directory Domain Services (AD DS)

    • Domain Name System (DNS)

    • Dynamic Host Configuration Protocol (DHCP)

    • File Server

    • Web Server

  • Clients: Devices that request and use data from servers.

Domain Name System (DNS)

  • Function: Translates website names (e.g., www.example.com) into IP addresses (e.g., 192.0.2.1).

  • Process:

    1. Type a domain into the browser.

    2. DNS locates the corresponding IP address.

    3. The connection is made to the web server to load content.

The World Wide Web (WWW)

  • Definition: The collection of public websites connected to the Internet.

  • Key Components:

    1. HTML (Hypertext Markup Language): Standard markup language for web pages.

    2. HTTP (Hypertext Transfer Protocol): Protocol for transferring web pages; uses Port 80.

    3. Web Servers & Browsers: Applications that facilitate navigation and presentation of web information.

Searching for Information on the Web

  • Web Administration: Managing websites and content.

  • Search Techniques: Various methods to enhance web searches, including:

    1. Subject directories

    2. Search engines

    3. Bots for automation (like Google's)

Additional Activity

  • Activity 3: Research an application with both web and mobile versions. Compare layout and design differences by the due date of April 24, 2025.