A zone file is the file stored on name server which provides information about the domains on that name server. Zone file contains the list of Domain Name Records with mappings between domain names and respective IP addresses. These records show the IP address of a domain name, reverse lookup of an IP to other domains and mail server information etc. Zone files are plain text files. Zone files must be stored on highly secured server because if unauthorized users gain access to zone files, these files can be easily modified.