Introducing images and instances
To understand images and instances a bit better, we first need to travel a little back in time; don't worry, a couple of years back is quite enough! This was the time when there was a boom in the implementation and utilization of the virtualization technology!
Almost all IT companies today run their workloads off virtualized platforms such as VMware vSphere or Citrix XenServer to even Microsoft's Hyper-V. AWS, too, got into the act but decided to use and modify a more off the shelf, open sourced Xen as its virtualization engine. And like any other virtualization technology, this platform was also used to spin up virtual machines using either some type of configuration files or some predefined templates. In AWS's vocabulary, these virtual machines came to be known as instances and their master templates came to be known as images.
By now you must have realized that instances and images are nothing new! They are just fancy nomenclature that differentiates...