imagetemplate of a virtual machine containing an installed operating system, software, and configuration stored as a file on disk
instancelaunched image of a virtual machine - a running server
flavorthe size of a running instance; i.e. #core, RAM, disk
hypervisorthe host server that the instance runs on; something akin to a software defined hardware compute server
snapshotthe process of taking an instance and turning it to an image
object storea blob of bits; it has a starting address & a size. There may be metadata associated with the object. The data is consumed in a streaming manner.
block storea software defined entity akin to an unformatted hardware disk drive
filesystemhierarchical in nature, directories & files, ability to open, seek, read, write
persistent storageIf you pull the plug, it will still exist when power is restored. Safe to store data or state here.
ephemeral storageIf you pull the plug, it no longer exists. (Don’t put your crucial data here!!!)
Information as a Service (IaaS)
form of cloud computing that provides virtualized computing resources over the Internet. Read more...

Platform as a Service (PaaS)

cloud computing model that delivers applications over the Internet.

Software as a Service (SaaS)

software distribution model in which applications are hosted by a vendor or service provider and made available to customers over a network, typically the Internet.Read more...
Volumessmall virtual filesystems that may be attached to running instances.Read more...