Instances is a great starting point for taking advantage of self service features and spinning up both vms and containers. In Morpheus it may be advisable to cover the definition of a few terms used within the application so as to reduce confusion.
Instance - A set of containers or virtual machines that can correlate to a single horizontally scalable entity or a service suite like a database. (It is important to note that an instance can contain one or more containers/vms depending on the instance type and configuration).
Container - Typically a docker container provisioned via a Morpheus Docker host.
Virtual Machine - A virtualized compute server provisioned onto various hypervisor hosts.
The instance catalog is the one stop shop for selecting items to be provisioned and pieced together. It contains not only basic container and vm options but also tailored services for SQL databases, NoSQL databases, cache stores, message busses, web servers, and even full fledged apps. The list contains a lot of items to choose from and they are represented to the user based on what provisioning engines are enabled and integrated in the Morpheus environment.