DevSecOps is a methodology that integrates security practices into the DevOps pipeline to ensure increased productivity and reduced risk. It involves shifting security left by including it from the beginning, which helps reduce friction and delays in the development process. Advantages of DevSecOps include reducing risk and legal liability, identifying bugs and vulnerabilities earlier in the process, and making security more manageable. Proper implementation requires organizational culture change, management buy-in, and training for all team members. The DevSecOps lifecycle includes various stages with specific actions, processes, and tools to achieve its objectives.