DHCP is Dynamic Host Configuration Protocol which use to assign the IP address Dynamically and Automatically in system
All the IP configuration information gets automatically configured for your machine by the Router.
If you move your machine to a different subnet, your computer will send out its discover message the next time it is turned on and work as usual. However, when you first boot up there will not be able to get back the IP address you had at your previous location regardless of how little time has passed.
Your machine name does not change when you get a new IP address. The DNS (Domain Name System) name is associated with your IP address and therefore does change. This only presents a problem if other people try to access your machine by its DNS name.