There are no sharp borders, it's basically about size and claim. see Scripting_language

For me (!) a script is a short efficient hack which is supposed to just do a little job and doesn't have to meet quality criteria of larger projects (lifespan, modularity, clear scopes and namespaces (i.e. no global vars), encapsulation, documentation, maintainability, and so on ...)

Sometimes scripts evolve into larger programs where all this quality aspects have to be added, but there is no magical byte added in this process, which turns a script into a "real" program.

PS: Yeah and it's also a flame topic, because some people try to vilify Perl as "only a script language". But in the context of this board it's no fun, better try vi vs emacs for some action. ;-)