Generally speaking, all runtimes have been traditionally called programs. (On Unix systems runtimes are often synonymous to executables. I guess the term runtime is used more often by devs on the Windows and Java platform, and I think it is specifically an antonym of library, but not sure because I don’t develop on those often) Applications traditionally referred to programs that were exposed to the user through a mouse interaction by intention. On macOS an app has the .app extension and is thus a special type of a program.

Although, depending on the context, an “application” might just mean programs because even official tech manuals aren’t perfectly rigorous.

On Linux and Windows it is similar. They don’t have a specific extension (some .exe binaries on Windows are meant to be run through the commandline.)

Software is the antonym of hardware, as I wrote in another comment.

Honestly I’m surprised that people here don’t share this. The terminology was rather cleanly separated before iPhone. Unfortunately, due to smartphones the word “app” entered the mass population and it lost meaning as usual.