Final answer:
A program that translates high-level language code into separate machine language is called a compiler. It converts human-readable code into instructions a computer's processor can execute, through several optimization stages.
Step-by-step explanation:
A program that translates a high-level language program into a seperate machine language program is known as a compiler. A compiler takes the code written by programmers (high-level language) and converts it into machine language, which is the set of instructions that a computer's processor can execute directly. This process is essential for turning human-readable code into a format the computer can understand and act upon. There are various stages involved in compilation, including lexical analysis, parsing, semantic analysis, optimization, and code generation, all aiming to optimize the machine-level program for better performance.