Say you want to use an Azure DevOps pipeline to build your containerized app. This scenario is of course supported and you would leverage all the built-in stuff (built-in container image, default container tasks, hosted build agent, etc.). You can even choose between the UI or YAML to configure the build pipeline.
Azure is Microsofts cloud platform. It is the home of Service Apps, Logic Apps, cloud storage, Kubernetes Service and provides the foundation for VSTS (now Azure DevOps), Office 365 and loads of other services and tools.