idk who started the concept of DNS changes "propagating" but I wish they hadn't

DNS is a query response system with intermediate caching layers, there is no propagation in the technical sense

i even see people who should know better use this terminology

people understand the term caching, use that instead!

in my experience non-technical users seem to understand that their web browsers cache content so if you want a similar concept to explain DNS caching with, use that

simplifying concepts for non-technical users is fine but "propagation" is just incorrect, its a disservice to use it

the only time DNS "propagates" is when you have a primary authoritative system using AXFR/IXFR to transfer zone updates to secondaries

and even then, if you have your systems configured properly, there is very little delay because your primary sends a "notify" to all your secondaries and they pull the new zone and if they use IXFR instead of AXFR which all modern auth nameservers use, its only a incremental transfer of the zones' updates and not the entire zone

i wrote an entire post about DNS TTLs and caching

its pretty good in my not so humble opinion

https://nullrouted.space/2021/11/18/understanding-dns-ttls-and-caching/