Supply chain security in DevSecOps focuses on protecting every component involved in building, delivering, and running software such as source code, third-party libraries, container images, CI/CD tools, and cloud infrastructure. It ensures that only trusted, verified, and vulnerability-free components are used throughout the pipeline. DevSecOps teams implement practices like dependency scanning, SBOM generation, artifact signing, access control, and continuous monitoring to prevent tampering and malicious injections. By embedding these controls early, organizations reduce risks from compromised dependencies and tools. Learning these practices through DevSecOps Training helps professionals build secure, compliant, and resilient software delivery pipelines.