TTL refers to Time to Live. It indicates the time after which the DNS records for a particular domain are refreshed and the cache is reset. TTL affects global DNS propagation by deciding how long the propagation process takes. If the TTL is set high, it means that the propagation will take a long time. For example, if you make changes to a DNS record that has a TTL of 3600 seconds, it means that the changes will be globally propagated after 1 hour. For 1 hour, the old records will stay in place