ACR stands for Azure Container Registry. It is a PaaS resource which encapsulates the management of container images, such as Docker images in the Microsoft Azure Cloud. ACR is tightly integrated to other container services in Azure, such as AKS. An AKS cluster can utilize an ACR registry to pull its container images from. An ACR supports image push and pull operations and can be managed by using Azure Entra ID permissions. It is an equivalent service to other known container image registries such as Docker Hub.