DevOps is a contraction of the terms "developer" and "system operator". Devops teams consist of developers, testers and application systems managers, and each team is responsible for developing and running one or more business applications or services.
The whole team is responsible for developing, testing, and running their application(s). In case of incidents with the applications under their responsibility, every team member of the DevOps team is responsible to help fix the problem. The DevOps philosophy is “If you built it, you run it”.
While DevOps is typically used for teams developing and running functional software, the same philosophy can be used to develop and run an Infrastructure platform that functional DevOps teams can use. In an infrastructure Devops team, infrastructure developers design, test, and build the infrastructure platforms and manage their lifecycle; infrastructure operators keep the platform running smoothly, fix incidents, and apply small changes.