ThefirstvolumeofthePOSApatternseriesintroducedabroad-spectrumofgeneral-purposepatternsinsoftwaredesignandarchitecture.Thesecondnarrowedthefocustofundamentalpatternsforbuildingsophisticatedconcurrentandnetworkedsoftwaresystemsandapplications.Thisvolumeusesdesignpatternstopresenttechniquesf