ESF supports caching (remembering) the results of some security requests. This can improve performance, sometimes dramatically, by eliminating some calls to the configured Security Managers.
There are two types of ESF caching. The ESF manager itself can cache results. When a request matches one in the ESF cache, the ESM Modules are not called, and the cached result is returned. ESF also has a mechanism for ESM Modules to cache information that may be expensive to retrieve, but currently no ESM Modules make use of that feature. That means caching is only active if it is enabled in the ESF configuration, not in the security manager configuration.