EnterraHost
DNS records are what turn a domain name into somewhere to go. The toolbox holds them for any domain whose DNS we run, and the Domains page links straight into the record editor for each one.
Every record has the same three parts. A name, a type, and a value. Once those three make sense, the rest is detail.
The types you will actually use
An A record points a name at an IPv4 address. This is what makes a website load.
A CNAME points a name at another name rather than at an address, and the other name is then resolved. It is useful when the target's address may change, because you inherit the change rather than having to make it. It cannot be used on the root of a domain, only on a subdomain, and that trips people up.
An MX record says where mail for the domain should be delivered. If you run mail with us, these are the records that point it at our servers, and adding SPF, DKIM and DMARC covers the separate records that authorise your domain to send.
A TXT record holds free text, and it is how a great many unrelated things prove you control the domain. Site verification for search engines is one, and the SPF policy is another., and the SPF policy among them.
A AAAA record is the IPv6 equivalent of an A record. Adding one is not required, and testing whether you and your site speak IPv6 is the way to find out whether yours matters yet.
The name field confuses more people than the value
The @ symbol means the domain itself, with nothing in front. So an A record named @ on yourbusiness.com is the record for yourbusiness.com.
Anything else in the name field is a subdomain, and it is normally written without the domain on the end. To create www.yourbusiness.com you enter www, not the whole name. Entering the full name usually creates a record called www.yourbusiness.com.yourbusiness.com, which resolves for nobody and looks correct in the list.
Time to live, and why to lower it
Every record carries a time to live, which is how long a resolver may keep the answer before asking again. A long one means fewer lookups and slower changes. A short one means the opposite.
For records you are about to change, lowering the time to live first is worth the small effort. It shortens the window where some of the internet still holds the old answer, and it means a mistake is undone in minutes rather than hours. Put it back up once the change has settled.
A DNS lookup from five regions shows what resolvers are actually serving, which is the only way to tell a change that has not propagated from one that was never saved.
Where the records live matters
Editing records only works where we hold the DNS. If a domain's nameservers point somewhere else, the toolbox may still show the domain while the records that count are at that other provider, and changes here will have no effect.
The Domains page names the DNS provider for each domain, so this is checkable before you spend time on a record that cannot help. If you want the DNS here, changing nameservers is the job that moves it, and it changes nothing else about the domain.