Is it a Perl program or a Perl script?
Larry doesn't really care. He says (half in jest) that "a script is what you give the actors. A program is what you give the audience."
Originally, a script was a canned sequence of normally interactive commands--that is, a chat script. Something like a UUCP or PPP chat script or an expect script fits the bill nicely, as do configuration scripts run by a program at its start up, such .cshrc or .ircrc, for example. Chat scripts were just drivers for existing programs, not stand-alone programs in their own right.
A computer scientist will correctly explain that all programs are interpreted and that the only question is at what level. But if you ask this question of someone who isn't a computer scientist, they might tell you that a *program* has been compiled to physical machine code once and can then be run multiple times, whereas a *script* must be translated by a program each time it's used.
Perl programs are (usually) neither strictly compiled nor strictly interpreted. They can be compiled to a byte-code form (something of a Perl virtual machine) or to completely different languages, like C or assembly language. You can't tell just by looking at it whether the source is destined for a pure interpreter, a parse-tree interpreter, a byte-code interpreter, or a native-code compiler, so it's hard to give a definitive answer here.
Now that "script" and "scripting" are terms that have been seized by unscrupulous or unknowing marketeers for their own nefarious purposes, they have begun to take on strange and often pejorative meanings, like "non serious" or "not real programming". Consequently, some Perl programmers prefer to avoid them altogether.