Definition
DNS propagation is the time it takes for a DNS change to become visible across all resolvers worldwide. When you update a DNS record, your authoritative nameserver has the new value immediately, but resolvers that have the old value cached will continue serving it until the TTL expires. Propagation is complete when all major resolvers worldwide have refreshed their caches. Typical time: minutes to 48 hours depending on TTL.
Use the tool: Propagation Checker — check dns propagation for any domain.