Vamos listar alguns casos de uso particulares e entender qual é o estilo de instância EC2 ideal para cada um dos caso de uso.
In dedicated Instances 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.
https://stackoverflow.com/questions/64309679/aws-dedicated-host-vs-dedicated-instance-why-the-first-is-more-expensive-than