Bytecode is an intermediate, low-level representation of a program that is executed by a virtual machine, such as the Java Virtual Machine (JVM) or the Python Interpreter. It is a compact and efficient format that bridges the gap between human-readable source code and machine-executable binary code.

How Bytecode Works:
Compilation: Source code written in high-level programming languages (e.g., Java, Python) is compiled into bytecode by a compiler.
Execution: The virtual machine reads and interprets the bytecode, translating it into machine code specific to the host system.
Portability: Since bytecode is platform-independent, it can run on any system with the appropriate virtual machine.
Characteristics:
Intermediate Representation: Bytecode is not directly executable by the hardware; it requires a virtual machine or interpreter.
Portability: Code written once can run anywhere (e.g., Java's "write once, run anywhere" philosophy).
Optimization: Bytecode is often optimized for faster execution compared to interpreting source code directly.
Use Cases:
Java: The Java compiler converts source code into .class files containing bytecode, which the JVM executes.
Python: Python compiles scripts into .pyc files containing bytecode for execution by the Python Interpreter.
Smart Contracts: In Ethereum, smart contracts are compiled into EVM (Ethereum Virtual Machine) bytecode.
Advantages:
Platform Independence: Enhances software portability across diverse environments.
Security: Allows runtime checks and sandboxing to prevent malicious activities.
Efficiency: Combines the flexibility of high-level languages with the performance of low-level execution.
Bytecode plays a crucial role in enabling cross-platform compatibility and efficient program execution in modern software ecosystems.