procedure, not module - and actually, process within a procedure -indeed any process that may go wrong
let's say you want to open a disk file, and you execute a command called, lets say
"open file"
so you could get many errors
- the folder may not exist
- the file may not exist
- the file may already be in use
- the folder may be access-protected against you
- the file may be access-protected against you
- the channel you specify may already be in use
- your command may be written incorrectly
-probably loads more
all of these will generate run time errors that you can handle and inform your users what the problem is without either a) the programming just halting, as in a .de version, or b) the programme taking them to the debug window