Java is high levl means?

Question

and write one nd run everywher

Answer 1

Write once run anywhere means a Java code can be compiled in any platform/OS, no need to change the code.

Answer 2

In addition to what Christopher wrote, a low level language (like assembler or C) is very "close" to the hardware (CPU). For example, in order to write assembler code, you need to know what specific processor and operating system you write the code for. Assembler code for Ubuntu 64 Bit with an AMD processor won't run on a 32 Bit Windows system and vice versa. Even with C++, you might get problems if you don't know if the system you run your code on uses Big Endian or Little Endian byte order etc. The more "high level" you get, the less you need to care about stuff like that. Your Java code will run on every device with a Java VM installed and get the same results everywhere.