DNS propagation refers to the amount of time that is required for updating the latest DNS data (DNS records) completely through the entire network of servers on the web. When you make modifications and adjustments to your DNS records, they are not immediate. The reason for that is because the various nameservers keep the DNS data (DNS records) inside their cache memory for a particular amount of time before they refresh. So while your domain won’t experience any downtime from appropriately planned DNS record modifications, some of the users could still be served a cached version of your website. That will continue until the DNS propagation is completed. Learn more additional information about DNS propagation!