A set of practices combining software development and IT operations. It aims to shorten the development life cycle and provide continuous delivery to customer/end-users.
Dev - C,B,T
Ops - D,O,M
Release ↔ Plan
Continuous Integration (CI): the practice of merging all developer’s code very frequently together, often in a master branch.
Continuous Delivery (often used for CD): approach in which teams produce software in short cycles, ensuring that the software can be reliably deployed/released at any time. Deployment to prod env is done manually (delivering).
Continuous Deployment (sometimes uesd for CD): approach in which software is deployed more often using automated deployments. Deployment to prod env is fully automated here.
Reference: Wikipedia Articles
Integrating security into every stage of SDLC. Security practices spans both development and operations in DevSecOps.
Tools - Sonarqube, Veracode, Twistlock, etc…