The document discusses and compares caching technologies for Java applications, specifically Memcached and DistributedMap. It provides an overview of general object cache characteristics and how cache instances work. Memcached is described as an open-source, high-performance distributed memory caching system where each cluster of servers is a single cache instance. DistributedMap is a built-in component of WebSphere Application Server that allows for multiple cache instances within a single JVM. The document outlines some advantages of each system and poses some open questions for further performance comparisons.