ULA addresses in IPv6 allow unique local addresses that can be used by a large enterprise to build their own network, so that they have specific IPv6 endpoints

ULA addresses in IPv6 allow unique local addresses that can be used by a large enterprise to build their own network, so that they have specific IPv6 endpoints always available, and then when their ISP hands them a different /64 or /56 they can continue to function as normal without renumbering.