Development and Operations combined - practices that unify software development and IT operations for faster, more reliable releases. Like having builders and maintenance crews work together instead of separately.
DevOps teams use automation and collaboration tools to deploy new features multiple times per day instead of once per month.
DevOps is a set of practices and a culture, not a single cloud service. Each provider offers DevOps toolchains (CI/CD, IaC, monitoring) that enable DevOps ways of working.