There are many programming languages — C, C++, Pascal, BASIC,FORTRAN, COBOL, and LISP are just a few. These are all high-level languages. One can also write programs in low-level languagescalled assembly languages, although this is more difficult. Low-level languages are closer to the languageused by a computer, while high-level languages are closer to human languages.
A program is like a recipe. It contains a list of ingredients (calledvariables) and a list of directions (calledstatements) that tell the computer what to do with the variables. The variables can represent numericdata, text, or graphical images.(n) An organized list of instructions that, when executed, causes thecomputerto behave in a predetermined manner. Without programs, computers are useless.
Eventually, every program must be translated into a machine languagethat the computer can understand. This translation is performed by compilers, interpreters, andassemblers.
When you buy software, you normally buy an executable version of a program. This means that the program is already in machine language — it has already been compiledand assembled and is ready to execute.