DNS Time to Live (TTL)

DNS time to live (TTL) is a value in a Domain Name System record that tells caching resolvers how long they may retain that record before checking again. It is commonly measured in seconds. When a business moves its website to a different host, a lower TTL set ahead of a planned change may reduce how long some cached answers persist, but it does not guarantee an instantaneous worldwide switch. DNS propagation describes the broader process of updated answers becoming visible across caches and resolvers. TTL settings should be coordinated with the site's DNS provider, and changes should be tested to avoid interrupting the website or email.