To me a script is something which is parsed at the time of execution. A program is compiled in advance. There are numerous exceptions to this but to me it describes the essence of it.
For me, scripts are something I write quickly, don't put a lot of thought into, don't care if they have weird failure cases. More like a one-off thing.<p>If a "script" is critical, has to handle lots of error conditions, has to always have reasonable behavior, and is part of any kind of production setup, then it becomes more like programming.
It's used in different ways. I think it's original meaning was writing a script for a program, which means specifying high level behaviors like a movie script. Game engines are written in a programming language and then expose a scripting language to build the game rules, control the characters, and so on. For the web, scripting ends up being the front end, because it's specifying the behavior of the web page, and it's high level on the software stack of the browser. Of course now frontend is very complex and not so much scripting... which does make me wonder why companies don't create their own frontend scripting language on top of typescript or javascript.
Classically, I think that scripts are small/one-off bits that were written in an immediate language like Bash or maybe Python.<p>Scripts I think are meant to be run by tech people so might lack documentation, error checking, etc.<p>Often you'd write a script to set up the environment for a program; paths, environment variables, rotate previous logs and write PID files.
Small scripts can evolve, and if they are part of an important program, can be more complex.<p>Programmers tend to write programs, while system admins used to write the bulk of scripts.<p>I'm not sure these divisions are as clear anymore, but that feels like how things originally evolved.
A script is a type of program, they're not two separate classes of things.<p>I think classically a script is a program whose subunits are each complete programs ('commands') that operate on a shared environment, with shell scripting being the central example. The definition has since been expanded by way of analogy to include basically any interpreted program which may have side effects on its execution environment.
Notebook vs laptop, software developer vs softwar engineer vs programmer, app vs program. There might be a difference in definition but the average person uses the words interchangably.