Consider that you have a JDK version jdk1.8.0_xxx installed on your machine. When you install and configure an Oracle Fusion Middleware product, the utilities, such as Configuration Wizard (config.sh|exe), OPatch, or RCU point to a default JDK, for example, jdk1.8.0_xxx. After some time, Oracle releases a newer version of the JDK that carries security enhancements and bug fixes. You can upgrade the existing JDK to a newer version and have the complete product stack point to the newer version of the JDK.

You can maintain multiple versions of JDK and switch to the required version on need basis.

• About Updating the JDK Location After Installing Oracle Analytics Server
  The binaries and other metadata and utility scripts in the Oracle home and Domain home, such as RCU or Configuration Wizard, use a JDK version that was used while installing the software and continue to refer to the same version of the JDK. The JDK path is stored in a variable called JAVA_HOME which is centrally located in .globalEnv.properties file inside the ORACLE_HOME/oui directory.