IAST stands for
Interactive application security testing
It is a testing approach in which the code is analyzed for security vulnerabilities while the application is run either by humans or by an automated test.
Vulnerabilities are reported in real-time, which implies that no extra time is added to the CI/CD pipeline.
IAST combines the advantages of SAST as well as DAST approach as it involves analyzing the source code from a static point of view as well as analyzing the execution flow of the application during runtime.