Can you explain what a low-coupling code between components is?

Low coupling code means that system components depend on each other minimally. This increases flexibility, makes testing and maintenance easier.

Example:

• Components communicate through well-defined interfaces rather than directly with each other's internal details.
• Changes in one component minimally affect others.

For example, if you have a class that depends on an interface rather than a specific implementation, you can easily replace the implementation without changing the code that uses this interface.

interface PaymentProcessor {
    void processPayment(double amount);
}

class PaypalProcessor implements PaymentProcessor {
    public void processPayment(double amount) {
        // implementation via PayPal
    }
}

class OrderService {
    private PaymentProcessor paymentProcessor;

    public OrderService(PaymentProcessor paymentProcessor) {
        this.paymentProcessor = paymentProcessor;
    }

    public void checkout(double amount) {
        paymentProcessor.processPayment(amount);
    }
}

Here, OrderService does not depend on a specific payment method, only on the interface, which reduces coupling.