A DNS cache is a cache of the result of a DNS lookup (query).
The cache is implemented in a DNS library by the resolver.
You need to configure the resolver to configure or purge your cache.
chrome://net-internals/#dns
To clear your local DNS cache, you have to type
ipconfig /flushdns
This is important when you try to troubleshoot a network problem because if a name is already cached it won't try and resolve the name again.