A caching proxy is a type of proxy server that caches (stores) frequently requested web pages, files, or other resources on the server’s memory. When a client requests a resource, the caching proxy checks if it has a copy of that resource in its storage. If it does, it can significantly reduce the amount of network traffic and improve the response time for subsequent requests.
Caching proxies are commonly used in organizations to reduce the load on their network and to provide faster access to frequently accessed resources. They can also be used by ISPs to provide faster access to frequently accessed websites and reduce the amount of bandwidth used by their customers.
See also: DNS query, DNS record, DNS resolution