you are locking down a single piece of hardware just for your purposes.
Dedicated Instance does not work like this. Your instance runs on some dedicated hardware. Its not lockdown to you. If you stop/start instance, you can get some other hardware somewhere else. Basically, the hardware is "yours" (you are not sharing it with others) for the time your instance is running. You stop/start it, you may get different physical machine later on (maybe older, maybe newer, maybe its specs will be a bit different), and so on. So your instance is moved around on different physical servers - whichever is not occupied by others at the time.
With Dedicated Host the physical server is basically yours. It does not change, it's always the same physical machine for as long as you are paying.
Answer from Marcin on Stack OverflowVideos
you are locking down a single piece of hardware just for your purposes.
Dedicated Instance does not work like this. Your instance runs on some dedicated hardware. Its not lockdown to you. If you stop/start instance, you can get some other hardware somewhere else. Basically, the hardware is "yours" (you are not sharing it with others) for the time your instance is running. You stop/start it, you may get different physical machine later on (maybe older, maybe newer, maybe its specs will be a bit different), and so on. So your instance is moved around on different physical servers - whichever is not occupied by others at the time.
With Dedicated Host the physical server is basically yours. It does not change, it's always the same physical machine for as long as you are paying.
Dedicated Host
As soon as you 'allocate' a Dedicated Host, you start paying for that whole host.
A host computer is very big. In fact, it is the size of the largest instance of the selected family, but can be divided-up into smaller instances of the same family. ("You can run any number of instances up to the core capacity associated with the host.")
Any instances that run on that Host are not charged, since you are already being billed for the Host.
That is why a Dedicated Host is more expensive than a Dedicated Instance -- the charge is for the whole host.
Dedicated Instance
"Dedicated Instances are Amazon EC2 instances that run in a virtual private cloud (VPC) on hardware that's dedicated to a single customer... Dedicated Instances may share hardware with other instances from the same AWS account that are not Dedicated Instances."
This means that no other AWS Account will run an instance on the same Host, but other instances (both dedicated and non-dedicated) from the same AWS Account might run on the same Host.
Billing is per-instance, with a cost approximately 10% more than the normal instance charge (but no extra charge if it is the largest instance in the family, since it requires the whole host anyway).
Hi guys are dedicated hosts basically an entire physical server rack that customers can select and can choose which individual physical server in rack that the instances can be deployed on ? Is dedicated instances basically instances that are running on the same physical server on a shared rack ? Each time a dedicated instance is stopped started , it goes onto a new physical server which only the company can spin up new vms ?