Frontend & Backend Architecture

Learning objectives

• Distinguish frontend, backend, and database layers
• Explain why separation of concerns matters
• Recognize static and dynamic content

The three layers

Almost every web application can be thought of in three layers:

• Frontend: what the user sees - HTML, CSS, and JavaScript.
• Backend: the application logic that processes requests - often PHP, Node.js, or Python.
• Database: where structured data is stored and queried.

This separation is called layered architecture. It makes systems easier to build, test, and maintain because each layer has a single responsibility.

Static versus dynamic

A static site serves the same files to every visitor. A dynamic application builds its pages per request, pulling data from a database. The right choice depends on the goal: a landing page may be static, while an e-commerce storefront is inherently dynamic.

// A tiny dynamic example (PHP)
$product = fetch_product($_GET["id"]);
echo render_product_page($product);

Why architecture matters

Well-structured code is cheaper to change and easier to secure. Poor architecture is the hidden cost behind slow feature releases and fragile systems. This is the discipline we bring to every custom build.

Key takeaways

• Frontend, backend, and database are distinct, cooperating layers.
• Choose static or dynamic delivery based on the goal.
• Clean separation of concerns reduces long-term cost.