DNS zone file

Hello.

Im pretty new to hosting files.

Ive recently bought a domain registered in Ireland with the when i go to change the name servers to the ezyro.com servers i get an email from the register saying error redelegating the name servers.

i contacted the company and they said that i require a DNS zone file in the root. Im not to sure what this is.

Ive already Hosted and have one webpage live with Profreehost but thats a .com domain s i think its because its a .ie domain..

any help would be gratefully accepted..

Regards in advance.

Keith.