Web Development Fundamentals

Web development is the process of building and maintaining websites. It encompasses a variety of skills and disciplines in the production and maintenance of websites. Here’s a comprehensive guide to the fundamentals and essential knowledge for web developers:

What is a Server?

A server is a computer system or device that provides resources, data, services, or programs to other computers, known as clients, over a network.

Types of Servers:

  • Web Server: Hosts websites and delivers web pages to clients via HTTP/HTTPS.
  • Database Server: Provides database services to other computer programs or computers.
  • File Server: Stores and manages files for network users.
  • Mail Server: Manages and transfers emails over a network.

Example:

When you type “www.example.com” in your browser, a request is sent to the web server hosting the website, which then sends back the requested web page.

Client-Server Architecture

Client-server architecture is a network structure where clients (user devices) request services and resources from a server.

Diagram:

Client (Browser) <---> Internet <---> Server

Components:

  • Client: The user interface device (like a browser) that requests resources.
  • Server: The system providing resources or services to the client.

HTTP Requests and Responses

HTTP (HyperText Transfer Protocol) is the foundation of any data exchange on the Web.

HTTP Request Methods:

  • GET: Requests data from a server.
  • POST: Submits data to be processed to a server.
  • PUT: Updates data on a server.
  • DELETE: Deletes data from a server.

HTTP Response Status Codes:

  • 200 OK: The request was successful.
  • 404 Not Found: The requested resource could not be found.
  • 500 Internal Server Error: The server encountered an error.

Example Request-Response Cycle:

  1. Request: Client sends a GET request to http://example.com.
  2. Response: Server responds with status code 200 and the requested HTML page.
GET /index.html HTTP/1.1
Host: www.example.com

HTTP/1.1 200 OK
Content-Type: text/html

<html>
<body>
<h1>Welcome to Example.com!</h1>
</body>
</html>

Front-End Development

Front-end development involves creating the part of the website that users interact with directly.

Core Technologies:

  • HTML (HyperText Markup Language): Structures the content.
  • CSS (Cascading Style Sheets): Styles the content.
  • JavaScript: Adds interactivity to the content.

Example:

<!DOCTYPE html>
<html>
<head>
  <title>Example Page</title>
  <style>
    body { font-family: Arial, sans-serif; }
  </style>
</head>
<body>
  <h1>Hello, World!</h1>
  <p>This is a simple web page.</p>
  <script>
    console.log('Page loaded');
  </script>
</body>
</html>

Back-End Development

Back-end development involves creating the server-side logic and database interactions.

Core Languages:

  • Python: Often used with frameworks like Django or Flask.
  • JavaScript (Node.js): Server-side JavaScript environment.
  • Java: Used in large-scale applications.
  • PHP: Widely used for web development.

Example (Node.js with Express):

const express = require('express');
const app = express();

app.get('/', (req, res) => {
  res.send('Hello, World!');
});

app.listen(3000, () => {
  console.log('Server running on port 3000');
});

Databases

Databases store and manage data for websites and applications.

Types of Databases:

  • SQL Databases: Structured Query Language databases (e.g., MySQL, PostgreSQL).
  • NoSQL Databases: Non-relational databases (e.g., MongoDB, CouchDB).

Example (SQL Query):

SELECT * FROM users WHERE user_id = 1;

APIs

APIs (Application Programming Interfaces) allow different software systems to communicate with each other.

Example:

A weather application fetching data from a weather API:

GET /weather?city=Kathmandu
Host: api.weather.com

HTTP/1.1 200 OK
Content-Type: application/json

{
  "city": "Kathmandu",
  "temperature": "22°C",
  "condition": "Sunny"
}

Web Development Tools

Various tools assist developers in building, testing, and maintaining websites.

Essential Tools:

  • Code Editors: VSCode, Sublime Text.
  • Version Control: Git, GitHub.
  • Browser DevTools: Inspect and debug web pages.
  • Package Managers: npm, yarn for JavaScript libraries.
  • Frameworks: React, Angular for front-end; Django, Express for back-end.

Summary

Web development involves a combination of front-end and back-end technologies. Understanding how servers work, how HTTP requests and responses function, and being familiar with development tools are all crucial for building and maintaining modern web applications.

Quiz

1. What does a web server do?

  • Stores and retrieves emails.
  • Hosts websites and delivers web pages.
  • Manages and organizes files.
  • Provides database services.

2. Which HTTP method is used to update data on a server?

  • GET
  • POST
  • PUT
  • DELETE

3. What are the core technologies of front-end development?

  • HTML, CSS, Python
  • HTML, CSS, JavaScript
  • JavaScript, SQL, PHP
  • HTML, PHP, CSS

4. Which of the following is a NoSQL database?

  • MySQL
  • PostgreSQL
  • MongoDB
  • SQLite

5. What is the purpose of APIs?

  • Style web content.
  • Structure web content.
  • Allow software systems to communicate.
  • Manage database interactions.

6. Which tool is used for version control?

  • npm
  • Git
  • VSCode
  • Express

7. What is the role of back-end development?

  • Create user interfaces.
  • Style web pages.
  • Handle server-side logic and database interactions.
  • Debug web pages.

Complete this quiz to test your understanding of web development fundamentals!

Last updated on Sep 9, 2018