What does it mean to "compile" code?

Compiling code refers to the process of transforming code written in a high-level programming language, which is more understandable to humans, into machine code or binary, which is executed by a computer's CPU. This conversion is crucial because CPUs can only execute instructions in their native machine language.

The compilation process typically involves several steps, including lexical analysis, syntax analysis, semantic analysis, optimization, and code generation. Once the code is compiled, the resulting machine code can be run efficiently by the processor. This step typically enhances performance compared to interpreting the code directly at runtime.

Other options describe distinct concepts in software development. Writing code in a plain text file refers to the formatting of the source code but does not involve any form of translation that preparing the code for execution entails. Running code without conversion refers to the interpretation of scripts, common in languages such as Python or JavaScript, where code is executed on the fly rather than pre-compiled. Lastly, formatting code for readability relates to styling and organizing the code for clarity, ensuring that it is easy to read and maintain, but does not involve any conversion to machine code.