Answer Description

NSLOOKUP will return the IP Address of a domain name by querying a computers assigned DNS Servers for the information. NSLOOKUP is well known as a Windows command but can be used on some Unix based systems as well.

Wikipedia

nslookup (from "name server lookup") is a network administration command-line tool for querying the Domain Name System (DNS) to obtain the mapping between domain name and IP address, or other DNS records.