Load testing vs. stress testing vs. performance testing?

Performance Test - A performance test is done to verify that an IT system performs according to the non-functional requirements.
If non-functional requirements are not available a performance test can be done to verify the actual performance before a release.

Per definition ”Load Testing” and “Stress Testing” are two types of Performance Tests.

Load Test - A test that generates transactions to a targeted application with intention of verifying how the application reacts to a specific load.

Stress Test- A stress test is a performance test where the level of load is increased over the expected load in production.
The focus of the test can be to see how a specific function is handling high-load or as a test that generates production-like transactions with a higher than expected throughput.
The goal is to identify what part of the architecture design is limiting the performance and if the application recovers when the load is decreased.