Options for Hosting Containers in Azure

Info here is compiled & paraphrased from various sources that are hyperlinked. Please refer back to the official sources for the latest information as this topic is constantly evolving

Image from the Azure Developer Guide

Containers are a relatively new kind of virtualization called operating system virtualization. Machine virtualization takes a single machine and simulates lots of machines. Containers take a single operating system installation (physical or virtual machine) and simulate lots of operating system installations.

Containers offer near-instant deployment and are a great way of moving legacy code into a DevOps lifecycle.

Deployment times are shortened, maintenance is easier, and scale-out/in is possible in seconds

Containers in Azure:

Azure Service	Features
Azure Kubernetes Service (AKS)	Scale and orchestrate containers using Kubernetes, DC/OS or Docker Best for Linux-based containers Multiple containers per VM As a free service, AKS does not offer a financially-backed service level agreement. We will strive to attain at least 99.5% availability for the Kubernetes API server. The availability of the agent nodes in your cluster is covered by the Virtual Machines SLA.  Suitable architecture styles - Microservices, Event-driven architecture ACS will be deprecated around the time that AKS becomes GA AKS reduces the complexity and operational overhead of managing Kubernetes by offloading much of that responsibility to Azure.  Azure Kubernetes Service offers portal, command line, and template driven deployment options (Resource Manager templates and Terraform). AKS clusters are Role-Based Access Control (RBAC) enabled by default. An AKS cluster can be deployed into an existing VNet. Node autoscaling is not supported but is on the roadmap.
Azure Container Instances	Easily run containers on Azure with a single command Serverless way of doing containers. Azure manages the host VMs No dedicated instances SLA - 99.9% Suitable architecture styles - Microservices, task automation, batch jobs ACI is not intended to be an orchestrator. However, you can combine the elastic scale of ACI with the orchestration capability of Kubernetes by using the ACI Connector for Kubernetes Per-second billing model. Cost effective for occasionally running workloads (will cost more for continuously running workloads)
Azure Container Registry	Store and manage container images across all types of Azure deployments Also provides additional capabilities, such as Azure Active Directory-based authentication, webhook support and delete operations. At least 99.9% of the time Managed Registry will successfully process Registry Transactions.
Azure Service Fabric	Develop microservices and orchestrate containers on Windows or Linux Windows and Linux containers can use Service Fabric but it is best suited to Windows. Besides containers, it can also host services, guest executables  Auto-scaling through VM Scale Sets Service Fabric is a free service, therefore, it does not have a financially backed SLA itself. The availability of your Service Fabric cluster is based on the SLA of the underlying virtual machines and storage resources used. Suitable architecture styles - Microservices, Event-driven architecture
Azure App Service	Deploy web applications on Linux using containers Web App for Containers uses the Docker container technology to host both built-in images and custom images as a platform as a service You cannot create Web App for Containers in an App Service plan already hosting non-Linux Web Apps. The Basic & Standard service plans with Linux runtime environments support Web App for Containers. SLA - 99.95%
Azure Batch	Run repetitive compute jobs using containers Container-based tasks in Batch can also take advantage of features of non-container tasks, including application packages and management of resource files and output files.

Image Source: official Azure documentation; click to view enlarged image

Related:
Comparison of Azure Compute Services
Comparison of Compute options in GCP