WHY DOES C/C++ GIVE BETTER RUN-TIME PERFORMANCE THAN JAVA?

Java is completely based on OOP’s that mean the whole java technology is work on the concept of Java Virtual Machine that is JVM that is main part of java compile, that acts as translators of byte code into machine language and compile the code. The work of JVM converts the Java byte codes into platform specific machine language that is the main concept of java. Java technology is high-level, object-oriented, very robust programming language. Java is platform independent programming language and you can run your compiled code on any machine without recompiling your source code

Although java is very robust language but c and c++ give better run time performance than java:

That’s because the Java bytecode is interpreted, not compiled. Programs written in C are compiled into binaries which can be executed by a specific computer processor. Programs
written in Java require one more step — they must be interpreted by the Java “virtual machine” before running. As a result, a computer running a Java program has to execute more
machine-language instructions to do the same amount of work than a computer running an equivalent program written in C.