Two additions to our guides section.

DNS Caching and TTL Explained covers how resolvers store answers, what a TTL value means, and why a record can keep resolving to the old address for a while after you change it. It includes a worked TTL countdown and a table of typical TTL values.

What Your IP Address Reveals About You walks through what a single IP lookup can show: approximate location, the network operator behind it, and reverse DNS. It also notes the common assumptions that are not accurate, so you know where the limits are.

Both are reference guides rather than news, and they link back to the resolver and leak-test tools where relevant.