Code is a source file written by programmers in the language supported by development tools. It is a set of clear rules, and information is represented in discrete form by characters, symbols or signal elements. The principles of code design include uniqueness, standardization and universality, expansibility and stability, easy identification and memory, short and unified format and easy modification. Source code is a branch of code. In a sense, source code is equivalent to code. The source code is relative to the target code and executable code. Source code is ground code written in assembly language and high-level language. Object code refers to the binary code that can be directly recognized by the cpu after the source code is compiled. Executable code is an executable file formed by connecting the target code, which is of course binary.