What defines an "executable" file in a terminal ls listing?

[Ged99]

When executing the command "ls -FlR" from a terminal window some filenames are appended with a *. According to the documentation, this means they are an "executable". But what does this mean? A few of my .pdf files are appended like this, but are just pdf files and not executable at all.



-rwxrwxrwx 1 Ged staff 921556 20 Aug 13:31 Scanned at 20-08-2020 13-11.pdf*

-rw-r--r--@ 1 Ged staff 556495 7 Dec 2018 2018_ks2_mathematics_Paper1_arithmetic.pdf

 

[Cory Cooper]

Hello and welcome.

Yes, the asterisk denotes a file as executable, so I am not sure why it would flag a PDF as executable. Could it possibly be password-protected?

C