Over time, GlassFish has evolved into a server platform that is much more than the reference implementation of the Java EE specifications. It is now a highly configurable server that is capable of delivering high quality of service. Now, let's understand the main components of GlassFish, and how they are organized to provide a complete server environment. As we see in this section, depending on the usage profile being used, the architecture of GlassFish varies slightly.
If you followed the installation instructions provided in Chapter 1, Getting Started, then the GlassFish Server was installed with the developer profile. The developer profile of GlassFish is very light, and its architecture is illustrated in the following figure. Now let's get familiar with the two essential components of GlassFish, the server instance and the administrative domain, shown in the following figure.