A domain name server maintains a directory of domain names and their matching IP addresses. This information allows other computers to know where to go to find your website. The NS record contains the name server information for the zone file.
MX Records [mail Exchange Records]
Mail Exchange Record. Creates a mail route for a domain name.
A domain name can have multiple mail routes, each assigned a priority number. The mail route with the lowest number identifies the server responsible for the domain. Other mail servers listed will be used as backups.