What it is
Reads the registration record for the domain: the registrar it was bought through, when it was created and when it expires, the status codes currently set on it, and the nameservers it delegates to.
Why it matters
Dates are the strongest signal here. A domain registered three weeks ago behaves very differently from one that has been renewed since 2004. Status codes show whether it is locked against transfer, or sitting in a grace period after expiry.