Domain Name In Zone File. By default this is varnamed. If you want each of these subdomains to point to your VPS server then change the IP address for each of them.
Go to the DNS Management page. In a new browser tab or window sign in to your DNS hosting provider and then find where you manage your DNS settings eg Zone File Settings Manage Domains Domain Manager DNS Manager. Also when you dig for a domain the default answer you get is a A record which is denoted by a capital A.
To put it simply the DNS zone file is where the data of the DNS Zone is the file so we can say that the DNS zone and the DNS zone file is one and the same.
DNS zone files are defined in RFC 1035 and RFC 1034. You can use zone files to get a representation of all the records of a particular domain. Also when you dig for a domain the default answer you get is a A record which is denoted by a capital A. It is the highly used resource record in a zone file.