Once the program is written and has had any errors repaired (a process called debugging), it may be executed in one of two ways, depending on the language. With some languages, such as C or Pascal, the program is turned into a separate machine language program by a compiler, which functions much as an assembler does. Other languages, such as LISP, do not have compilers but use an interpreter to read and interpret the program a line at a time and convert it into machine code. A few languages, such as BASIC, have both compilers and interpreters. Source code, the form in which a program is written in a high-level language, can easily be transferred from one type of computer to another, and a compiler or interpreter specific to the machine configuration can convert the source code to object, or machine, code.
The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.