Java, Java SE, Java ME, Java EE

Java Se:java Standards Edition, Standard Edition, Development desktop application. Java, which is often said, is also the core.
Java Ee:java Enterprise Edition, Business Edition, developing Javaweb applications.
Java Me:java Micro Edition, miniature version, the development of mobile phones and other electronic products applications.

Q:java is an interpreted language, so inefficient and has 2 ways to improve performance:
After the 1.Java language source program is written, the Java pseudo-compiler is used for pseudo-compilation, which is converted to an intermediate code (also known as bytecode) and then interpreted.
2. Provide a "quasi-real-time" (just-in-time,jit) compiler, you can use the JIT compiler to convert bytecode to machine code when faster speed is required,
Then cushion it down so that it will be faster.

Java, Java SE, Java ME, Java EE