• Translate high-level program (source language) into machine code (machine language)
• Slow translation, fast execution
• Compilation process has several phases:

• lexical analysis: converts characters in the source program into lexical units
• syntax analysis: transforms lexical units into parse trees which represent the syntactic structure of program
• Semantics analysis: generate intermediate code
• code generation: machine code is generated

Load module (executable image): the user and system code together

Linking and loading: the process of collecting system program and linking them to user program