The Big Picture: How the Web Works
The web is a massive network of interconnected devices that communicate using standardized protocols. Understanding how it works at a high level involves looking at key components and their interactions.
1. The Internet vs. the Web
- The Internet is the global network of computers.
- The Web (World Wide Web – WWW) is a system of information sharing over the Internet, using web pages linked together via URLs (Uniform Resource Locators).
2. Key Components of the Web
a. Clients (Users’ Devices)
- Devices like laptops, smartphones, and tablets.
- Use browsers (Chrome, Firefox, Edge) to access web pages.
b. Servers
- Computers that store and serve web pages.
- Handle requests from clients and return data.
c. HTTP & HTTPS (Protocols)
- HyperText Transfer Protocol (HTTP): Rules for communication between clients and servers.
- HTTPS (Secure HTTP): Encrypts data using SSL/TLS for security.
d. DNS (Domain Name System)
- Translates human-readable domain names (e.g.,
google.com) into IP addresses (e.g.,142.250.190.46).
e. HTML, CSS, JavaScript
- HTML (HyperText Markup Language): Structures web pages.
- CSS (Cascading Style Sheets): Styles web pages.
- JavaScript: Adds interactivity and dynamic behavior.
3. How a Web Page Loads (Step-by-Step)
- User enters a URL (e.g.,
www.example.com). - Browser contacts a DNS server to get the website’s IP address.
- Browser sends an HTTP request to the server.
- Server processes the request and sends back HTML, CSS, and JavaScript files.
- Browser renders the web page using these files.
4. Frontend vs. Backend
- Frontend (Client-Side): What users see and interact with (HTML, CSS, JS).
- Backend (Server-Side): Handles logic, databases, and security (Node.js, Java, Python, PHP).
5. Databases
- Web applications often store and retrieve data using databases like MySQL, PostgreSQL, MongoDB.
6. APIs (Application Programming Interfaces)
- Allow websites to communicate with each other (e.g., fetching weather data from an external service).
7. Web Development & Frameworks
- Frontend frameworks: React, Angular, Vue.js.
- Backend frameworks: Express.js, Django, Spring Boot.
8. Security & Performance
- CDN (Content Delivery Network): Distributes content for faster access.
- Caching: Stores data temporarily for faster loading.
- Security measures: HTTPS, firewalls, authentication.
