Introduction
What is Full Stack Development?
A full stack developer is a software engineer capable of working on every layer of a web application — the visual interface users interact with (frontend), the server logic that processes data (backend), and the database that stores everything. The term "stack" refers to the complete set of technologies layered together to form a working application.
Think of it like a building: HTML/CSS/JavaScript form the facade, PHP and Node.js form the structure, and MySQL/MongoDB form the foundation. A full stack developer can design, build, and maintain all of these layers independently.
Think of it like a building: HTML/CSS/JavaScript form the facade, PHP and Node.js form the structure, and MySQL/MongoDB form the foundation. A full stack developer can design, build, and maintain all of these layers independently.
Architecture
The Four Layers
Every web application is built in layers. Hover each layer to explore:
Presentation Layer — Frontend
What the user sees and interacts with in the browser.
↕
Application Layer — Backend
Server logic, routing, authentication, business rules.
↕
Data Layer — Database
Persistent storage, queries, relationships.
↕
Infrastructure Layer
Hosting, deployment, scaling, CI/CD pipelines.
Interactive Demo
The Request–Response Cycle
Click each step to trace a web request through the entire stack:
Click the steps to explore
1
User types a URL or clicks a button
2
Browser sends HTTP GET/POST request
3
PHP/Server processes the request
4
Database is queried (SQL/NoSQL)
5
Server builds HTML/JSON response
6
Browser renders the content for the user
Backend Example — PHP
PHP Server-Side Scripting
PHP (Hypertext Preprocessor) is a server-side scripting language that runs on the web server before the page is sent to the browser. It can read form data, query databases, manage sessions, and dynamically generate HTML.
PHP Login Handler with MySQL
PHP 8
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<?php
// Connect to MySQL database
$conn = mysqli_connect("localhost", "root", "", "myapp");
// Check connection
if (!$conn) {
die("Connection failed: " . mysqli_connect_error());
}
// Sanitise user input (security!)
$username = mysqli_real_escape_string($conn, $_POST['username']);
// Query the users table
$sql = "SELECT id, name FROM users WHERE username='$username'";
$result = mysqli_query($conn, $sql);
if (mysqli_num_rows($result) > 0) {
$row = mysqli_fetch_assoc($result);
echo "Welcome, " . $row['name'];
}
Comparison
Frontend vs Backend vs Full Stack
| Skill Area | Frontend Dev | Backend Dev | Full Stack |
|---|---|---|---|
| HTML / CSS | ✓ Expert | ✘ Basic | ✓ Expert |
| JavaScript | ✓ Expert | ~ Partial | ✓ Expert |
| PHP / Server Logic | ✘ None | ✓ Expert | ✓ Proficient |
| MySQL / Databases | ✘ None | ✓ Expert | ✓ Proficient |
| REST APIs | ~ Consume only | ✓ Build & Consume | ✓ Both |
| Deployment / DevOps | ✘ Rarely | ~ Partial | ✓ Proficient |
Technology Stacks
Popular Stacks
LAMP
Linux · Apache · MySQL · PHP
The classic web stack, still powering millions of sites. Our curriculum is built on this stack.
The classic web stack, still powering millions of sites. Our curriculum is built on this stack.
MERN
MongoDB · Express · React · Node.js
A modern JavaScript-everywhere stack popular for SPAs and real-time apps.
A modern JavaScript-everywhere stack popular for SPAs and real-time apps.
MEAN
MongoDB · Express · Angular · Node.js
Enterprise-ready full-JS stack with Angular's structured approach.
Enterprise-ready full-JS stack with Angular's structured approach.
JAMstack
JavaScript · APIs · Markup
Static-first architecture with dynamic functionality via APIs.
Static-first architecture with dynamic functionality via APIs.