JavaScript is an interpreted language. That it, is not compiled into an executable file destined for a specific computing platform. Compiled languages run faster, however they are not as flexible as interpreted languages. There is some debate on which is easier to debug. A JavaScript code set will work with any platform that runs a JavaScript enabled browser.

If a program is interpreted, its actual human-readable source is read as it is run by the computer. This is generally a slower process than if the program being run has already been compiled.

As opposed to compiled, interpreted means the Prolog system attempts to prove a goal by directly reading the clauses rather than executing instructions from an (abstract) instruction set that is not or only indirectly related to Prolog.

A scripting language, such as Basic and its many "flavors," as well as Python, Tcl, and Javascript, has its programming code "interpreted" into computer instructions every time a script is run (at "run time"). An executable program, one that comes complete unto itself, has had all of its computer instructions "compiled" just once. C/C++, Pascal, Delphi/Kylix, and Java are examples of compiled languages.

Python is an interpreted language, as opposed to a compiled one. This means that the source files can be run directly without first creating an executable which is then run. Interpreted languages typically have a shorter development/debug cycle than compiled ones, though their programs generally also run more slowly. See also interactive.