Module 5: Internet Applications

I. Introduction

The advent of the internet has revolutionized the way we communicate, access information, and conduct business. Internet applications, ranging from web browsing and email to social media and online banking, have become integral to daily life. This module delves into the foundational concepts of internet applications, exploring their evolution, underlying technologies, and the mechanisms that enable data distribution across the globe.

II. Connectivity in the New Millennium

The new millennium ushered in an era of unprecedented connectivity. Advancements in networking technologies, such as broadband, Wi-Fi, and mobile data, have facilitated seamless access to the internet. This ubiquitous connectivity has fostered the proliferation of internet applications, enabling real-time communication, e-commerce, and the Internet of Things (IoT). As a result, individuals and organizations can interact and collaborate irrespective of geographical boundaries, leading to a more interconnected world.

III. The Web and HTTP

The World Wide Web (WWW) is a system of interlinked hypertext documents accessed via the internet. At the heart of the web lies the Hypertext Transfer Protocol (HTTP), which defines the rules for transferring web pages from servers to clients (browsers). HTTP operates as a request-response protocol: a client sends an HTTP request to a server, which then responds with the requested resource. This protocol underpins the functionality of web browsers, enabling users to navigate between web pages through hyperlinks.

IV. The URL

A Uniform Resource Locator (URL) serves as the address of a resource on the internet, guiding users and applications to specific web pages, images, or downloadable files.

Parts of a URL

A standard URL comprises several components:

1. Scheme (Protocol): Indicates the protocol used to access the resource, such as http or https.
2. Subdomain: An optional segment that precedes the main domain, often denoting a specific subdivision of a website (e.g., blog in blog.example.com).
3. Second-Level Domain (SLD): The main domain name chosen by the registrant (e.g., example in example.com).
4. Top-Level Domain (TLD): The suffix indicating the domain category, such as .com, .org, or country codes like .ph for the Philippines.
5. Port (Optional): Specifies the port number on the server; if omitted, defaults like 80 for HTTP and 443 for HTTPS are assumed.
6. Path: Defines the specific resource’s location on the server (e.g., /about-us).
7. Query Parameters (Optional): Key-value pairs following a ? that provide additional information to the server (e.g., ?search=internet).
8. Fragment (Optional): An anchor within the resource, indicated by a #, directing to a specific section of a page (e.g., #section2).

Examples of Domain Names and Their Descriptions

• example.com: A generic domain often used in documentation and tutorials to represent a placeholder website.
• harvard.edu: The official domain for Harvard University, indicating an educational institution.
• bbc.co.uk: The British Broadcasting Corporation’s domain, with .co.uk signifying a commercial entity in the United Kingdom.
• gov.ph: A domain used by governmental agencies in the Philippines, with .gov.ph denoting a government entity.

V. How Data is Being Distributed Over the Internet

Data distribution over the internet involves a complex interplay of protocols and technologies to ensure efficient and reliable delivery of information. When a user requests data, such as accessing a website, the following process typically unfolds:

1. DNS Resolution: The Domain Name System (DNS) translates the human-readable domain name into an IP address, directing the request to the appropriate server.
2. Data Routing: The request traverses multiple routers and networks, guided by Internet Protocol (IP), to reach the destination server.
3. Server Processing: The server processes the request, retrieves the necessary data, and prepares it for transmission.
4. Data Transmission: Using protocols like HTTP or HTTPS, the server sends the data back to the client, often employing data compression and caching to optimize delivery.
5. Rendering: The client (e.g., a web browser) receives the data and renders it for the user, completing the cycle.

This intricate process ensures that data is accurately and swiftly distributed across the vast expanse of the internet, enabling seamless user experiences.

V. Conclusion

Understanding the components and mechanisms of internet applications is crucial in today’s digital age. From the structure of URLs to the protocols governing data transmission, each element plays a pivotal role in the seamless operation of online services. As technology continues to evolve, staying informed about these foundational concepts will empower individuals and organizations to navigate and leverage the internet effectively.

References

• Berners-Lee, T., Fielding, R., & Masinter, L. (1998). Uniform Resource Identifiers (URI): Generic Syntax. Internet Engineering Task Force. Retrieved from https://datatracker.ietf.org/doc/html/rfc2396
• Concrete CMS. (2024). Breaking Down the Parts of a URL. Retrieved from https://www.concretecms.com/about/blog/devops/breaking-down-the-parts-of-a-url
• Hostwinds. (2023). 11 Parts of a URL: A Complete Guide. Retrieved from https://www.hostwinds.com/blog/11-parts-of-url-complete-guide
• HubSpot. (2023). Parts of a URL: A Short Guide. Retrieved from https://blog.hubspot.com/marketing/parts-url
• Mailchimp. (2023). Beginner’s Guide To The 10 Parts Of A URL. Retrieved from https://mailchimp.com/resources/parts-of-a-url/
• Registered Agents, Inc.