## Explaining 9 types of API testing

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- Smoke Testing   
    This is done after API development is complete. Simply validate if the APIs are working and nothing breaks. 
- Functional Testing   
    This creates a test plan based on the functional requirements and compares the results with the expected results. 
- Integration Testing   
    This test combines several API calls to perform end-to-end tests. The intra-service communications and data transmissions are tested. 
- Regression Testing   
    This test ensures that bug fixes or new features shouldn’t break the existing behaviors of APIs. 
- Load Testing   
    This tests applications’ performance by simulating different loads. Then we can calculate the capacity of the application. 
- Stress Testing   
    We deliberately create high loads to the APIs and test if the APIs are able to function normally. 
- Security Testing   
    This tests the APIs against all possible external threats. 
- UI Testing   
    This tests the UI interactions with the APIs to make sure the data can be displayed properly.
- Fuzz Testing   
    This injects invalid or unexpected input data into the API and tries to crash the API. In this way, it identifies the API vulnerabilities.