System and method of accessing a document efficiently through multi-tier web caching

A client-server network system implements a multi-tier caching strategy for a user to access a document efficiently. When serving a document to client, the document is examined for embedded references to other documents. The embedded references are extracted and then assigned a priority. The documents referenced are obtained locally from the server cache or obtained from their respective web hosts and transmitted according to the assigned priority. If the client determines that it has the document, the transmission of is terminated. If the client or server determines that a newly requested document is one of the referenced documents being transmitted, the transmission is given a higher priority. In some instances, the server calculates a content difference between a current version of a referenced and a previous version and transmits this content.