Also referred as non-functional, they check that the application performs successfully well in terms of capacity, availability, security and so on to meet users' needs.

Many projects do not treat their requirements the same way as other tests. Users will be very upset if their credit card is stolen or website is down due to capacity problems.

Stress

• Purpose: Stress testing checks the system's behavior under intense loads and conditions, exceeding its specified limits. The goal is to identify the breaking point and ensure the system fails gracefully.
• Implementation: Use tools like JMeter, LoadRunner, or Locust to generate extreme loads. For example, if a website typically handles 1,000 concurrent users, test it with 5,000 or 10,000 to see how it behaves. Monitor system metrics like CPU, memory, and response times to determine bottlenecks.

Performance Testing

• Purpose: To ensure the system performs optimally under load and stress.
• Implementation: Use tools like JMeter or LoadRunner to simulate multiple users accessing the system simultaneously. Monitor response times, throughput, and system stability under varying load conditions.