Openshift is Red Hat's container management system. It's equivalent to Kubernetes. Openshift uses a GUI, whereas Kubernetes uses CLI.

Containers virtualize operating systems. VMs virtualize hardware resources.

There are a lot of articles explaining each. Here's one by Microsoft

Do the two mix? Yes and no. You could run containers on VMs, but you don't always have to.

Docker isn't the easiest thing to set up on Windows and Mac but it's easier on Linux. In most cases, people use Windows and Mac. You could start a VM to run a Linux environment and spin up a Docker there.

Instead of running Docker on a VM, you could also do it on Red Hat's Openshift. It allows you to manage multiple environments, standardize workflows across multiple dockers, and load balance.

A bit of community knowledge. In November 2019, Mirantis acquired Docker. It's meant to be free but Red Hat needs to diversify in case Docker begins charging fees. Openshift now supports CRI-O an alternative container to Docker. Organisations that deploy with Openshift will have the option to use either container.

Strangle the monolith. I like this term. It basically means breaking down a monolith into microservices, one service at a time. When this happens, each microservice needs to reconnect with each other through APIs. But how do you keep track of the changes when a monolith transitions into microservices? Openshift provides a Service Mesh to keep track of the relationships and outcomes. (Check out Netflix OSS).

One problem Service Mesh can help solve is cascading failures. When microservices are linked as a chain, a break in one service fails the entire chain. Having a birds-eye-view gives developers a glimpse of the microservice landscape.