Scripting languages (commonly called scripting programming languages or script languages) are computer programming languages that are typically interpreted and can be typed directly from a keyboard. Thus, scripts are often distinguished from programs, because programs are converted permanently into binary executable files (i.e., zeros and ones) before they are run. Scripts remain in their original form and are interpreted command-by-command each time they are run. Scripts were created to shorten the traditional edit-compile-link-run process. The name 'script' is derived from the written script of the performing arts, in which dialogue is set down to be interpreted by actors and actresses--the programs. Early script languages were often called batch languages or job control languages. Scripting languages can also be compiled, but because interpreters are simpler to write than compilers, they are interpreted more often than they are compiled.
The term scripting language is not technical, though embedding and dependence on a larger system are usually criteria. In computer games, scripts extend game logic, tailoring the game engine to particular game data. Scripts also make applications programmable from within, so that repetitive tasks can be quickly automated. Of course, not every scripting system that grows beyond its original design and delegation acquires a new name. Full-blown in-game languages such as UnrealScript exist, and JavaScript is a very influential standard, supported by virtually every browser on the market.
You can get the whole idea here :-
http://en.wikipedia.org/wiki/Scripting_language