In this chapter, you learned what WAS is and what it does in a Sametime environment. You learned the different concepts and terms used when referring to a WAS environment and deployment. You learned about the directory structure of WAS and what information is stored in each subdirectory in a Sametime environment. You learned how WAS security is implemented, as well as what directory options are possible. Finally, you learned about the different deployment configurations and the benefits associated with each one. In the next chapter, you will learn about the decisions you need to consider when planning for an installation of Sametime 8.5.2.