What is the DNS cache?

entries that translate Internet domain names

A DNS cache contains entries that translate Internet domain names *such as "compnetworking.about.com") to IP addresses. The Internet's Domain Name System (DNS) involves caching on both Internet DNS servers and on the client computers that contact DNS servers. These caches provide an efficient way for DNS to efficiently keep the Internet synchronized as the IP addresses of some servers change and as new servers come online.

know more
http://compnetworking.about.com/od/dns_domainnamesystem/f/what-is-a-dns-cache.htm

It translates entries into ip address.