Fundamentals of the Internet, World Wide Web, and Basic Web Architecture

A set of flashcards covering the fundamentals of internet infrastructure, the difference between the Internet and the World Wide Web, core web architecture, and HTTP status codes.

What is the nature and analogy of the Internet as described in the lecture?

The Internet is hardware and infrastructure, functioning as a massive global network of physical cables, routers, and computers; its analogy is the physical roads, highways, and bridges of a global city.

What is the World Wide Web (WWW) and its corresponding analogy?

The World Wide Web is software and data, consisting of a collection of digital pages and information accessed through the Internet; its analogy is the shops, houses, and businesses built alongside the roads.

In web architecture, what is the 'Client'?

The client is the user's device and software (such as a phone or browser) that acts as the customer ordering food.

What is a 'Server' in the context of web architecture?

A server is a highly powerful computer running $24/7$ that stores website files and "serves" them when requested, acting as the kitchen preparing the food.

What does ISP stand for and what is its role?

ISP stands for Internet Service Provider; it is the company you pay for internet access that owns the cables connecting your house, acting as the delivery drivers.

What is an IP Address?

An IP Address is a unique string of numbers given to every connected device, similar to a physical house having a postal address.

What is the Domain Name System (DNS)?

The DNS is the Internet's phonebook which translates human words (like google.com) into computer numbers (like $142.250.190.46$).

How are files transmitted over the internet according to the 'Navigation & Delivery' section?

The internet chops files into thousands of tiny digital envelopes called "packets," sends them independently, and then reassembles them.

What is HTTP and why is it significant?

HTTP (HyperText Transfer Protocol) is the universal set of rules that web browsers and web servers use to speak to one another seamlessly regardless of their operating system or manufacturer.

What specific command does a browser send during 'Step 1: The Request'?

The browser typically sends a "GET Request," which is analogous to a customer handing an order slip to a waiter in a restaurant.

What does the HTTP Status Code $200$ OK represent?

It means "I found what you asked for, here it is!"; the server successfully processed the request.

What does the HTTP Status Code $404$ Not Found indicate?

It indicates the server understood the request but does not have the requested file; the connection is fine, but the page is missing.

What does the HTTP Status Code $403$ Forbidden mean?

It means the server has the file, but the user does not have permission to see it, and access is actively blocked.

What are the four steps that occur in milliseconds when accessing a webpage?

$1.$ The Request, $2.$ DNS Lookup, $3.$ Packet Switching, and $4.$ Reassembly.

Who is credited as the inventor of the World Wide Web?

Tim Berners-Lee.