A Name server (NS) record indicates which server is authoritative for a particular domain. This means it's the record that provides information on which DNS server contains the actual data for the domain, such as the IP address associated with a given hostname. An Address (A) record maps a hostname to its corresponding IPv4 address, whereas a Canonical Name (CNAME) record is used to alias one name to another. A Mail Exchange (MX) record specifies the mail servers responsible for a domain's email services.