Sometimes a developer has to reset its DNS cache to avoid site preview errors (most of the time when a server transfer occurs). This article will explain how to flush DNS cache from your Mac! What is DNS? DNS, or the Domain Name System, translates human-readable domain names (for example, www.amazon.com) to machine-readable IP addresses (for example, 192.0.2.44). This article will explain how to flush DNS cache from your Mac!