This thread has evolved from my initial question, so I have updated the title to reflect.
My original question was:
I am assuming that they are referring to the ORACLE_HOME environment variable which is needed to install APEX successfully. This is an "environmental" setting that most be set for the scripts to concatenate the path names properly.
It is not entirely clear what Oracle means when it addresses ORDS installations which are used to communicate with APEX. Here is the link and excerpt.
Any ideas?
Installing Oracle REST Data Services
The Oracle Application Express architecture requires some form of web server to proxy requests between a web browser and the Oracle Application Express engine. Oracle REST Data Services satisfies this need but its use goes beyond that of Oracle Application Express configurations. Oracle REST Data Services simplifies the deployment process because there is no Oracle home required, as connectivity is provided using an embedded JDBC driver.