Delivery consists of an extended routine that is called once all the code that your application needs has been loaded in to LispWorks.
To deliver your application, you use the Application Builder tool in the LispWorks IDE, or run LispWorks on the command line with your build file which does all the necessary preparations (normally just loading patches and the application code) and then calls the function deliver.
LispWorks also provides sets of programming libraries and code supporting various other facilities that you may want to use in your application. Some of these facilities are available in the basic LispWorks image, while others are provided as modules and need to be loaded explicitly using
LispWorks Delivery User Guide - 10 Aug 2017