Source and Object Programs
A set of instructions in a high-level language are called “Source program”. Since high-level languages are machine independent, it is required to first convert them into machine language and only then the instructions can be executed. The software required to convert high-level language program into machine language is known as “Compiler”. Thus compiler translates a high-level language program (Source program) into machine language program, which is called an “Object Program”. The object program can be executed using data provided by the user to give the required results.
For each high-level language, a separate compiler will be required. Thus, for a computer system there may be a BASIC compiler, COBOL compiler, etc.