KWASU - CSC 101 Internet Technology

Chapter 1: Introduction to the Internet

  • Internet: A global system of interconnected computer networks using the standard Internet protocol suite (TCP/IP).

    • Definition: A vast network consisting of millions of private, public, academic, and government networks of varying scope.

    • Functions: Enables billions of users to access extensive information resources and services, such as the World Wide Web (WWW) and email infrastructure.

Computer Networks

  • Definition: Infrastructure that allows two or more computers (hosts) to communicate and exchange data.

    • Nodes: Each device on the network is a node with a unique address.

    • Protocols: A set of rules that govern communication, allowing diverse computer systems to communicate effectively.

Properties of Computer Networks

  1. Facilitate Communications

    • Methods include email, instant messaging, video conferencing, etc.

  2. Permit Sharing of Files and Data

    • Users can access and share files stored on other networked computers.

  3. Share Network and Computing Resources

    • Ability to utilize shared devices like printers in a networked environment.

  4. Security Risks

    • Vulnerable to hacking, viruses, and denial of service.

  5. Complex Setup

    • Setting up complex networks can be costly and challenging.

Why Networks?

  • Load Sharing: Distributes workloads across systems.

  • Message Service: Handles communication among users, like online messaging.

  • Data Sharing: Facilitates work with extensive databases.

  • Program Sharing: Allows sharing of software applications.

  • Remote Services: Provides functionalities to access systems remotely.

Network Terminologies

  • Intranet: A private network within an organization, accessible only to authorized users.

  • Extranet: A controlled network allowing outsiders access for business or educational purposes.

  • Local Area Network (LAN): Connects computers within a limited area, like a home or office.

  • Wide Area Network (WAN): Covers extensive geographical areas.

  • Enterprise Private Network: Connects various company sites for resource sharing.

  • Virtual Private Network (VPN): Provides secure connections through public networks.

Network Topology

  • Definition: Layout of the interconnections between nodes. Includes logical and physical arrangements.

  • Common Layouts:

    1. Bus Network: All nodes connected to a single medium.

    2. Star Network: All nodes connect to a central node.

    3. Ring Network: Each node connects to two others forming a circle.

    4. Mesh Network: Nodes connect to multiple neighbors.

    5. Fully Connected Network: Every node connects to all others.

History of the Internet

  • 1960s: The ARPANET was developed to create a secure communication network.

  • 1972: The first email was sent.

  • 1980s-1990s: Transition from NCP to TCP/IP facilitated the rapid growth of networks leading to today's Internet.

Role of the Internet in Modern Society

  • Communication: Offers global connectivity and interaction platforms.

  • Information Access: Revolutionized how information is disseminated and retrieved.

  • Commercial Development: Enabled online commerce, digital marketing, and consumer interaction.

Basics of File Transfer and Remote Computing

  • FTP (File Transfer Protocol): Used for transferring files; includes commands for login and file management.

  • TELNET (Remote Computing): Allows remote access to computers.

World Wide Web (WWW)

  • Definition: A hypertext-based information retrieval system allowing users to access interlinked resources.

  • Web Concepts:

    • Web Page: A document on the web presenting various types of information.

    • Website: Collection of web pages grouped together.

    • Uniform Resource Locator (URL): Complete web address that provides specific resource locations on the Internet.

Web Hosting and Search Engines

  • Web Hosting: Services necessary to store and maintain websites for user access.

  • Search Engines: Algorithms for locating and retrieving data from the Internet based on user queries.

Internet Protocols and Services

  1. TCP/IP: Main Internet communication protocol defining rules for network communication.

  2. HTTP/HTTPS: Protocols for resource exchange on the web, HTTPS being secure and encrypted.

  3. ISP (Internet Service Provider): Organization that provides Internet access/services.

Client-Server Architecture

  • Client: User's machine that requests files/services.

  • Server: Computer that provides requested resources and services.

Structure of Web Documents

  • HTML: Markup language used for structuring web pages; consists of various elements like headings, paragraphs, and lists.

  • Basic Structure:

<!DOCTYPE html>
<html>
<head>
<title>Document Title</title>
</head>
<body>
<!-- Content goes here -->
</body>
</html>

  • Headings: Defined with <h1> to <h6> tags for different levels of importance in content.

Useful HTML Tags and Attributes

  • Paragraphs: Defined by <p> tags to create separate text sections.

  • Links: Created using the <a> (anchor) element, with href specifying the destination.

  • Images: Inserted with the <img> tag, specifying src for image location and alt for description.

  • Forms: Used for collecting user input with various fields like text, radio buttons, and checkboxes.

  • Tables: For tabular data representation using <table>, <tr>, <td>, and <th> elements.

CSS in Web Design

  • Definition: Cascading Style Sheets is used for defining the visual presentation of web pages.

  • Key Properties:

    • Uses selectors to apply styles to HTML elements.

    • Can control layout, colors, fonts, and more.

    • Methods include inline, internal, and external stylesheet links.

Conclusion

  • The Internet and associated technologies (HTML, CSS, protocols) have transformed communication, data sharing, and commerce, making it an integral part of modern society.