A Record ( Address Mapping Record ) is a DNS record which maps a domain name to the IPv4 address of the server which hosts the domain. An A record is used for discovering the IP address of the server connected to Internet from a given hostname. You can associate same hostname with multiple IP addresses by adding another A Record with the same hostname although with a different value of IP address.
How to check an A record
Most DNS tools let you check the A record for your website. In fact, most online tools will first show you the A record for the domain, and next show you the NS records. This checking process is calling a DNS lookup. If you have a UNIX machine you can use the “dig” command to do a DNS lookup.
Editing the A record using Plesk
Plesk has a feature-packed DNS Management tool, here you can change any of your domain records. Setting the A record you want is simple. To edit the A record, visit the Custom DNS Records page and select the relevant domain. Next, open the drop-down menu and select “A” from the list of records. Type in the IP address that corresponds to the A record you are changing, edit the TTL to meet your requirements and click “Add New” to complete the action.