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💡(1) J.V.M (Java Virtual Machine)-

J.v.m = j.i.t(just-in-time compiler)+cache

💡-> J.v.m Doesn’t exists physically, It just resides in RAM

💡-> J.v.m provides specifications to execute java byte-code.

💡-> J.v.m is platform dependent and easily available for many platforms(OS)

Note – We can’t refer any particular file as windows, it’s a group of specifications which provides environment to run software, similarly JVM only runs Java compiled codes(bytecodes).

*JVM internal architecture*-

💡(2)JRE (Java Runtime Environment)-

💡–> implementation of JVM.

💡–> physically exists.

JRE = JVM + Set of libraries (i.e. jar) + Other Files

Note – To run java program we only need to install JRE, to develop java program we need to install JDK.

💡(3)JDK (Java Development Kit)-

💡–> physically exists.

💡 JDK = JRE + Development tools(i.e. javac, java etc)

Interview Questions —

• How to install JVM?
• Is Windows JVM different than Linux/Mac JVM?
• Does installing JDK automatically installs JRE and JVM ?