acts as a unique identifier for a single item (often the "top" or first item in a category).
In this secure model, the id is treated as data, not executable code. Whether the user requests ID 1 or ID 1000 , the database structure remains protected. php id 1 shopping top
// DANGEROUS CODE - Do not use $id = $_GET['id']; $query = "SELECT * FROM products WHERE id = $id"; acts as a unique identifier for a single