There is a tendency to think of the many cloud computing services as distinct products, each with its own functions, benefits and use cases. It may be more useful to think of them instead as the complementary layers of a single hybrid cloud services stack.

Infrastructure-as-a-Service (IaaS) solutions make up the base layer, providing organizations on-demand access to the servers, storage and networking they need. That is typically topped with a Platform-as-a-Service (PaaS) layer for developing, running and managing applications. Containers-as-a-Service (CaaS) often sits in the middle, tying everything together through simplified deployment of applications and highly efficient usage of system resources.

Containerization is a virtualization technique in which developers package an app and all its required runtime components in a small, portable bundle. By separating infrastructure from the application, containers can move freely between different clouds and physical and virtual environments without modifying any code. This “build once, use anywhere” model creates the application portability needed for multi-cloud and hybrid environments.

App containers can have a wide variety of contents, but the external packaging remains the same. Resource-sharing features allow containerized apps to access the CPU, memory, I/O and network resources of the host operating system. That means the apps and resources within the container can be written in any language or built on any framework.

CaaS solutions simplify the process of managing and deploying containers by not only delivering container engines and orchestration but also image repositories, service discovery, storage and network plug-ins, and other resources as a service. CaaS allows organizations to focus on developing and deploying containers while letting IaaS providers take on the task of maintaining and securing a consistent infrastructure across all environments.

With built-in orchestration engines such as Kubernetes and Docker Swarm, CaaS solutions enable scaling by spreading application loads evenly across host infrastructure. Additionally, cluster management features allow applications to run as clusters of containers that work together and can be viewed and managed as a single system.

Leading IaaS providers such as AWS, Microsoft Azure, Google, Red Hat OpenShift and Docker Cloud all have CaaS solutions built on top of their IaaS platforms. The major differentiator among providers is the underlying orchestration solution that automates clustering, load balancing, provisioning and more. Some offer a choice of orchestration engines such as Kubernetes, Docker Swarm and Apache Mesos, although others use proprietary APIs.

Many of the providers also have PaaS offerings, where developers write their code before deploying to CaaS. Organizations gain all the functionality they need to develop and implement containerized applications within a single cloud.

Nevertheless, CaaS, IaaS and PaaS are distinct services with different use cases and differing management models. With IaaS and PaaS, the customer’s management requirements go up the stack, while with CaaS they don’t really change. As with IaaS, the service provider is only responsible for the underlying infrastructure below the operating system.

That’s why it’s important for organizations to consider whether they even need containers before implementing CaaS. Containerization has many benefits but it increases complexity because it introduces components that IaaS doesn’t have.

Technologent can help you determine if CaaS can benefit your operations. We can develop a cloud architecture with the right layers to support your applications.