Java is a full computer language that is used to develop programs used on the computer and various computer devices. It runs on all types of electronic devices and many programs to control devices are written in Java. It is an advanced computer language that was developed by Sun and is now owned by Oracle. Java is an object oriented language which means different parts of programs developed in it relate to other objects and not being a language that always does stuff in a specific set of ordered steps. It works more like we humans really think and work.
You will get regular notices of updates need made to Java and if you are not running the current version of Java and it wants to update I would encourage you to do so, then you will have the security patched version.