What is the difference between the JVM, JRE and JDK [duplicate]

this question already has answers here : What does "run on the JVM" mean? (1 response) what is an SDK? (5 responses) Closed 1 year ago .

I've been researching and haven't quite understood the difference between them, especially between JRE and JDK.

The JVM would be like the heart of Java, and besides I've heard that it "doesn't exist physically", what do you mean? If it does not exist physically do JRE and JDK exist "physically"?

Why have JRE if JDK exists?

What is the difference between JVM, JRE and JDK?

And as an extra, are these acronyms masculine or feminine? I see several people talking" a "JVM / JRE / JDK, and others talking that the right one is "o". After all, which one is correct?

Author: NinjaTroll, 2019-12-16