A and AAAA records: where the website lives
An A record connects a name, such as yourbusiness.com, to an IPv4 address, the numeric location of a server. An AAAA record does the same for the newer IPv6 format. When you move hosting, the A record is often the main one that changes.
You may have one record for the bare domain and another for the www version. Make sure both lead to the right place, and that one redirects to the other so there is a single preferred address.
CNAME records: names that point to other names
A CNAME says one name is an alias for another. Many builders and services ask you to set www as a CNAME pointing to their address, so they can change servers without asking you to update anything. A CNAME cannot sit on the bare domain in standard DNS, and a name with a CNAME generally cannot have other record types.
This is why some providers ask for an A record at the root and a CNAME for www.
MX records: where email goes
MX records list the mail servers that accept email for your domain, with priority numbers. If you use Google Workspace or Microsoft 365, they provide specific MX values. Replacing your website host's DNS entries without copying the MX records is a classic way to lose email overnight.
Always write down or screenshot the existing records before changing anything.
TXT records: verification and email authentication
TXT records hold text. They prove you own the domain to services like Google Search Console, and they carry email authentication settings such as SPF, DKIM and DMARC. A domain can have many TXT records, but only one SPF record. Adding a second one is a frequent error that breaks authentication.
NS records, TTL and propagation
NS records name the servers that control your DNS. Change those and you are handing the whole phone book to a different provider, so everything must be recreated there first. TTL, or time to live, says how long others may keep your old answer. A lower TTL, set a day ahead of a planned change, makes updates take effect sooner.
After an edit, changes can take from minutes to a day or more to be seen everywhere, depending on caching. Lookup tools let you check what the world currently sees.
A safe habit: change one thing at a time, confirm it works, and keep a log of what you changed and when.
A quick example for a typical small business
Suppose a landscaper has a site on a builder, email with a business mailbox provider, and a booking tool on a subdomain. The DNS zone might contain an A record for the bare domain, a CNAME for www, a CNAME for book pointing to the booking vendor, two or three MX records, and TXT entries for SPF, DKIM and Google verification.
Seeing it laid out like this shows why a careless edit is risky: five different services depend on one list of entries, and each does a separate job.
Common questions
Who manages my DNS?
It is wherever your domain's name servers point, which may be your registrar, your host or a separate service. Look up your NS records to find out.
Can I break my email by editing website settings?
Yes, if MX or TXT records get deleted or replaced. Copy them before any change.
What does propagation mean?
It is the time it takes for caches around the internet to forget the old answer and pick up the new one.
This guide is general information. Search engines change how they work and their guidelines; check Google's current documentation for your situation. Nobody can guarantee a ranking.