DIFFERENCE BETWEEN FUNCTIONAL AND NON-FUNCTIONAL TESTING

The functional and non-functional testing both are necessary and important categories of software testing that help ensure the quality and reliability of a software application

Functional Testing:-

Functional testing focuses on verifying that the software functions correctly according to its specifications. The majority of this testing is done in a black box manner without touching the source code of the application.

Unit Testing: Testing individual components or functions in isolation.

Integration Testing: Verifying that different components/modules work together as expected.

System Testing: Testing the entire system to ensure it meets the specified requirements.

User Acceptance Testing (UAT): Checking if the software satisfies user requirements and expectations.

Non-Functional Testing:-

Non-functional testing its focuses on characteristics like performance, usability, reliability, and scalability.

Performance Testing: Evaluating how well the software performs under various conditions (e.g., load testing, stress testing).
Usability Testing: Assessing the user-friendliness of the software and its user interface.
Security Testing: Identifying vulnerabilities and ensuring the software is secure.
Reliability Testing: Testing the software’s stability and its ability to recover from failures.
Scalability Testing: Measuring how the software handles increased load or data volume.

Example of Functional and Non Functional Testing

Functional Testing Example:

For example for "Amazon" is the checkout process. In functional testing, we focus on this process to ensure it works as expected.

Test Scenarios:

1. Adding items to the cart: Users can select and add products to their shopping cart.

2. Applying discounts: The system correctly applies discount codes before finalizing the purchase.

3. Checkout process: The application successfully processes payment information and completes the order.

4. In each case, input specific data (e.g., product selection, discount code), and verify that the output matches expectations (e.g., cart total updates, discount applied, order confirmation received).

Non-Functional Testing Example:

For example for A mobile banking application is preparing for a major update. The development team conducts non-functional testing to ensure the update meets high performance, security, and usability standards.

Security Testing: Tests are performed to identify and fix vulnerabilities, ensuring user data is protected against unauthorized access.

Performance Testing: The application is tested under peak load conditions to guarantee smooth transactions during high traffic periods, like holidays.

Usability Testing: Feedback from a diverse user group is collected to refine the app’s interface, making it intuitive and easy to navigate for all users.

This focused approach to non-functional testing ensures the banking app is secure, efficient, and user-friendly, maintaining user trust and satisfaction with every update.