SAST is a type of application security testing that focuses on code. It works early in the CI pipeline and scans source code, bytecode, or binary code in order to identify problematic coding patterns that go against best practices. SAST is programming-language dependent.
DAST is a black-box testing method that scans applications in runtime. It's applied later in the CI pipeline. DAST is a good method for preventing regressions and doesn’t depend on a specific programming language. DAST fits best with application security testing methods that rely on static checks, like SAST and SCA, since it provides additional runtime insights to the static source-code analysis.
SCA focuses on third-party code dependencies that are used in the application. SCA is very effective in applications that use many open-source libraries. SCA is programming language-dependent.
IAST is essentially a combination of SAST and DAST application security testing methods. IAST analyzes only the code executed in your tests, like DAST, but it also pinpoints the exact place in the code where the vulnerability was found, as with SAST.
MAST is a type of application security testing that focuses on mobile apps. MAST combines static analysis, dynamic analysis, and penetration testing to effectively assess risk areas of the mobile app.