Stress Testing, Load Testing and Performance Testing consider as a non-functional testing types.

The non-functional testing types are the tests which measure how the system’s works. 

The criteria of evaluating inherited from the non-functional requirements.

There is an application which can handle 25 simultaneous transactions at a time, with a maximum response per transaction 10 seconds.

Example:

In load testing:

We will test the application for 25 users and check how application is working in this stage.

In performance testing

We will concentrate on the time taken to perform the operation.

In stress testing:

We will test with more users than 25 and the test will continue to any number and we will check where the application is cracking.

Regards,

Samer Desouky

ISTQB Certified Test Manager