The function of a compiler in programming is to translate high-level programming code into low-level machine code that a computer can understand and execute. Compilers analyze the source code, check for errors, and optimize the code, generating an executable file that runs on the target machine. This process typically involves several stages, including lexical analysis, syntax analysis, semantic analysis, and code optimization. By converting human-readable code into machine language, compilers enable developers to write in higher-level languages while allowing machines to perform tasks efficiently, thereby bridging the gap between programming logic and hardware execution.