What is API testing, and why is it important for QA testers?

H2K Infosys explains that API testing is the process of verifying that Application Programming Interfaces function correctly, securely, and efficiently. It focuses on validating data exchange, business logic, performance, and error handling without relying on a user interface. API testing is crucial for QA testers because modern applications depend heavily on interconnected services. It helps identify issues early, ensures seamless integration, and improves overall software reliability. Additionally, it enables faster testing cycles and supports automation, making it essential for agile and DevOps environments where continuous delivery and high-quality performance are critical to success.