The vocabulary.
PROVIDER
The company operating the service.
TENANT
A customer's isolated portion of a shared platform.
REGION AND AVAILABILITY ZONE
A geographic location, and an isolated facility within it.
INSTANCE
A virtual machine you run.
ELASTICITY
Capacity that adjusts with demand.
PROVISIONING
Creating a resource.
WORKLOAD
A piece of work the system performs: an application, a database, a process.
MULTI-TENANCY
Several customers sharing underlying infrastructure, isolated from each other.
VENDOR LOCK-IN
Difficulty leaving a provider because of dependence on their specific services.
MIGRATION
Moving systems or data between environments.
SLA
A service level agreement stating commitments and remedies.
EGRESS
Data leaving the provider, frequently charged.
That last one surprises people.
WHAT TO ASK ABOUT ANY TERM
What it means concretely for your bill and your obligations.