Client-Server Architecture
A deep understanding of client-server architecture is fundamental for any PHP developer, as it defines the entire paradigm of web application development. In this model, the client (typically a web browser) sends requests to a server, and the server (running PHP) processes those requests and returns a response. PHP's role is exclusively on the server side, handling the application logic, data processing, and business rules.
The Role of PHP on the Server
As a server-side language, PHP is responsible for handling incoming HTTP requests. A developer's tasks include routing requests to the correct controller, processing data from forms ($_POST) or URL parameters ($_GET), interacting with a database to retrieve or store information, and authenticating users. Once the processing is complete, PHP generates a response—usually HTML, JSON, or XML—to send back to the client.
Key Concepts and Responsibilities
Mastery of client-server architecture involves several key areas:
- API Design: Building RESTful or GraphQL APIs that clients can consume.
- Database Management: Writing efficient and secure SQL queries to interact with databases like MySQL or PostgreSQL.
- State Management: Using sessions and cookies to maintain user state across multiple requests.
- Security: Implementing measures to protect against common vulnerabilities like SQL injection and cross-site scripting (XSS).
