Static Application Security Testing (SAST) is a method of debugging by examining source code before the program is run, identifying vulnerabilities that could lead to security breaches. It is an essential part of a secure software development lifecycle, allowing developers to detect and fix security issues early in the development process, reducing the overall risk and cost of remediation.
Dynamic Application Security Testing (DAST) is a security testing methodology that analyzes applications in their running state to identify vulnerabilities by simulating external attacks. Unlike static testing, DAST does not require access to the source code and focuses on the application's exposed interfaces, making it effective for identifying runtime issues like authentication and server configuration errors.