Java language is simple because mostly syntaxlike C++ . Java removed pointers, operator overloading etc. No need Java has Automatic Garbage Collection which removes non referenced objects .
Java is an Object-oriented programming(OOPs) .The basic features of OOPs are as follows:
Java run on multiple platforms e.g.Windows,Linux Mac/OS etc. Write Once and Run Anywhere(WORA).
Java is secured because: It does not has explicit pointer.
Java has strong memory management. Is has automatic garbage collection.
We may carry the java compiled code( bytecode) to any platform e.g.Windows,Linux Mac/OS etc.
Multi-threading shares the same memory.