DNS (Domain Name System) is the component of the Internet that converts human-readable domain names (ie: example.com) into computer-readable IP addresses (ie: 22.214.171.124). DNS uses zone files that reside on your server to map domain names to IP addresses.
Note: To be able to edit records in your DNS zone at the registrar, you will need to point your DNS to the registrar’s nameservers.
What is an A record?
An A record is a DNS record that maps a domain to the physical IP address of the computer hosting that domain (the A in A record stands for Address). Internet traffic uses the A record to find the computer hosting your domain’s DNS settings. The value of an A record is always an IP address, and multiple A records can be configured for one domain name.
A records are essential because they allow DNS servers to identify and locate your website and its various services on the Internet. This allows the end user to type in a human-readable domain, while the computer can continue to work with numbers. To get to a web page, you possibly followed a link from another website pointing to example.com. In the DNS Zone Editor, the A record that points to example.com is an IP address. 126.96.36.199.
Without appropriate A records, not only will visitors be unable to access your website, but FTP and email accounts will also not function.
What is a CNAME record?
A CNAME record is an abbreviation for Canonical Name record and is a type of resource record in the DNS used to specify that a domain name is an alias for another domain, the “canonical” domain. A CNAME points one domain or subdomain to another domain name, allowing you to update one A Record each time you make a change, regardless of how many Host Records need to resolve to that IP address. All information, including subdomains, IP addresses, etc, are defined by the canonical domain. CNAME records allow an administrator to point multiple systems to one IP without specifically assigning an A record to each host name. If your server IP ever changes, you only have to change one A record’s IP address to update all associated records.
What is an MX record?
A mail exchanger record (MX record) is another type of resource record in the DNS that defines how email will be routed for your domain, and sets a preference value used to prioritize mail delivery if multiple mail servers are available.
You can have many MX records for a domain. The mail server will attempt to contact them in numeric order, starting at the lowest number. This lets you set up multiple values if you need more than one nameserver. If you have two records with the same value, the record that gets used will be chosen at random. If a lower valued record isn’t available, the next highest value will be used. Often times higher values are configured to only save the messages and then forward them on to the lower values when they become available again. Note: Heberdomaine’s hosting services use only a single MX record.
The set of MX records of a domain name specifies how email should be routed with the Simple Mail Transfer Protocol (SMTP). Like a CNAME, MX Entries must point to a domain and never point directly to an IP address.
What is a TXT record?
A TXT record is a type of DNS record that provides text information to sources outside your domain. A fully qualified domain name may have many TXT records. TXT records historically have also been used to contain human readable information about a server, network, data centre, and other accounting information. Some uses for TXT records are Sender Policy Framework (SPF), DomainKeys (DK), and DomainKeys Identified E-mail (DKIM).
You could set up a TXT record on example.com that contains the internet IP address of your computer at home; this would mean that mail claiming to be FROM: firstname.lastname@example.org is only allowed to be sent from your home IP.