Comment by yeukhon

OpenStack is a platform for creating an Infrastructure as a Service (IaaS). So it's running on some physical machines, and manages your physical machines to slice into VMs. There you get to manage / create networks, storage, etc. Basically running a private cloud in your own datacenter/basement/office. Openstack has grown more than just compute. It has a supposedly compatible interface for S3 an object storage system, for example. New components are created after major cloud services like AWS, pretty much. To manage containers or manage applications, you can use CloudFoundry/Kubernetes, but to manage the "infrastructure as a platform" (I want more machines, I want some bucket, I want to run some Lambda function, I want to upload new OS images) you need something like OpenStack. So if you want to build AWS/Digital Ocean, OpenStack is required.