The type checking of Java is at least as strong as that of C++, so that Java programs are well-checked at compile-time. Strong run-time checking by the interpreter catches many other errors. Type checking and interpretation make Java programs crash-proof. The program can fail, but not crash the rest of the system. Many of the errors that hang systems, such as bad subscripts and bad pointers, are specifically detected, preventing a Java program from damaging the rest of the system.
Consider the following links:
b) or back to Java is Interpreted
n) or next to Java is Secure
or
x) or out to Sun's Definition of Java