Compiling JSP files is resource intensive and time consuming. Precompiling JSP files before deploying applications on the server will improve application performance. When you compile in advance, only the resulting servlet class files will be deployed.
You can specify on the server to pre-compile JSP files when you deploy an application through the Admin Console,through CLI or GUI. You can also specify on the server to pre-compile JSP files for an already deployed application with the Admin Console.