DNS record types
A domain does not store a single piece of data, it stores several records of different types in the same zone, each answering a specific question: A returns the IPv4 address, MX returns the mail server, TXT returns free-form text. Each record type carries a number assigned by IANA, for example A is type 1 and MX is type 15, and that number is what travels in the binary query even when the interface only shows the letters.
The A type is DNS record number 1 in the IANA registry; the 3600 TTL decides how long resolvers keep this answer before querying again.
MX priority works backwards from intuition: the lower number is preferred, not the higher one; that is how a primary and backup mail server pair is set up.
A name with a CNAME can only have that single record; that is why a CNAME never sits at the domain root, where SOA and NS are mandatory, and why providers offer ALIAS/ANAME as a non-standard workaround.
A DNS lookup queries a domain's DNS records. It reveals a site's IP (A/AAAA), which servers receive its email (MX), email policies and verifications (TXT), the authoritative servers (NS) and much more. It's the first diagnostic step whenever a site or email stops working.
Because the root needs the zone's mandatory SOA and NS records, and a name with a CNAME cannot have any other record type at that same name; the workaround DNS providers offer is a non-standard extension like ALIAS or ANAME.
An A record points a name directly to an IPv4 address; a CNAME does not store an address, it points a name to another canonical name, which then has to be resolved again, usually ending in an A or AAAA.
The lower the number, the more preferred that mail server is; a domain often has more than one MX, each with a different priority, so the lowest-numbered server is tried first and the rest act as backups.
TXT stores free-form text tied to the name, and it is the format used by SPF, by the DKIM public key and by the DMARC policy, plus domain-ownership verification codes required by third-party services.
The query uses DNS-over-HTTPS (Cloudflare or Google) directly from your browser. Pick “Common” to see A, AAAA, MX, TXT, NS and CNAME at once, or a specific type. Enter an IPv4 address to run a reverse (PTR) lookup.
For safety, the browser talks directly to a fixed public resolver (Cloudflare or Google), passing only the queried name, the J-Kit server is never used as an intermediary, avoiding IP exposure and SSRF. A DNS query is public by nature, like any name resolution.