Summary full notes on JAVA

### Java Summary (Very Short Notes) - **Platform**: Object-oriented, platform-independent via JVM. - **Key Features**: Simple, secure, portable, robust, multi-threaded. - **Syntax**: Similar to C++, but simpler. - **Main Concepts**: - **Class & Object**: Core of Java. - **Inheritance**: Reuse code via "extends". - **Polymorphism**: Same method, different forms. - **Encapsulation**: Data hiding with private/protected access. - **Abstraction**: Focus on "what" over "how". - **Memory Management**: Automatic Garbage Collection. - **Execution**: `javac` for compilation, `java` for execution. - **API**: Rich libraries (Collections, IO, Networking). Widely used for web, mobile (Android), and enterprise apps.