What are namespaces used for in PHP?

Namespaces in PHP are used to address two main issues:

1. Avoiding name conflicts.
2. Simplifying code organization.

For example, a project may have two classes with the same name but different functions, located in different parts of the application. Without namespaces, this would lead to an error.

<?php

namespace App\Models;

class User {
    // User model logic
}

namespace App\Controllers;

class User {
    // User controller logic
}

// Without namespaces, this would cause a Fatal error: Cannot redeclare class User

Namespaces allow isolating class, function, and constant definitions, making the code more modular and preventing name collisions, especially when using third-party libraries.