DNS dictionary

Here are a few quick definitions to get you started:

A record A very common type of DNS record. It contains an IPv4 address, like
Authoritative DNS server This is one type of DNS server. Every domain has an authoritative DNS server assigned to it. The way DNS requests generally flow is:
you -> DNS resolver -> authoritative
                         DNS server
CNAME record A common type of DNS record. It contains an hostname address, like example.com. CNAME records comic.
DNS name Every time you type a domain, subdomain, or sub-sub-domain into your browser, that's a DNS name! A DNS name (like bananas.prince.fruit.oops.pie.com.) has to:
  • be less than 255 characters
  • have less than 63 "."s in it
  • be composed of only a-z, A-Z, 0-9, and "-" characters
  • and a couple of other rules
Other than that, DNS queries can contain any DNS name.
DNS record When you make a DNS query, you get 0 or more records in response. Every record has at least 4 fields: the name, the TTL, the type, and one or more content fields. For example the IP address in an A record is its content.
DNS resolver This is one type of DNS server. A resolver takes your request, sends it to the right authoritative DNS server, and caches the result. You might be using a resolver run by Google, Cloudflare, or your ISP.
DNS query A DNS query is a request that you send to a DNS server. It contains 2 fields: the name (like example.com), and the type (like "A").
Subdomain See DNS name
TTL Stands for Time To Live. This is a DNS record field. It's an number of seconds. DNS resolvers use it to decide how long to cache the record.