Continuous Deployments is the next stage of automation following on from it’s predecessors continuous integration (CI) and continuous delivery (CD).
The integration phase of the project used to be the most painful step, depending on the size of the project developers work on isolated teams dedicated to seperate components of the application for a very long time, when the time came to integrate those components a lot of issues, like unmet dependencies, interfaces that don’t communicate etc, are dealt with for the first time - the idea of CI was thought out to combat this problem.
Virtual Machines In the quest for maximising efficiency of computing power available on servers Virtual Machines (VMs) came into existence, with products from firms like VMware and Virtualbox pushing the concept to general users.
“In computing, virtualization refers to the act of creating a virtual (rather than actual) version of something, including virtual computer hardware platforms, operating systems, storage devices, and computer resources.” - Wikipedia
Virtual Machines are created on top of hypervisors which run on top of the host machine’s operating system (OS), the hypervisors allow emulation of hardrware like CPU, Disk, Memory, Network etc and server machines can be configured to create a pool of emulated hardware resources available for applications in the process making the actual harware resources on those server utilized much more efficiently.
