What It Is
DNS propagation is the time it takes for a DNS change to reach everyone. When you update a record, internet providers and devices around the world may still be using a saved copy of the old one. As those saved copies expire, based on the record’s TTL, they fetch the new version. It is like updating your address: some friends get the news right away, others a little later.
Why It Matters for Your Business
Propagation explains why, after moving a website or changing email providers, you might see the new site while a customer still sees the old one. Changes can appear in minutes, but a day or two is not unusual. During that window, avoid shutting down the old host so nobody hits a dead page.
Good to Know
To check, use an online DNS lookup tool that tests from several locations, rather than refreshing your own browser. Your computer may be holding its own saved copy. Clearing your browser cache, trying a phone on cellular data instead of Wi-Fi, or using a private browsing window can also help you see the current version of your site.