The World Wide Web can be considered as a large distributed information
system that provides access to shared data objects. As
one of the most popular applications currently running on the Internet,
the World Wide Web is of an exponential growth in size,
which results in network congestion and server overloading. Web
caching has been recognized as one of the effective schemes to alleviate
the service bottleneck and reduce the network traffic, thereby
minimize the user access latency. In this paper, we first describe
the elements of a Web caching system and its desirable properties.
Then, we survey the state-of-art techniques which have been used
in Web caching systems. Finally, we discuss the research frontier
in Web caching.
