When using a unix terminal, sometimes you make typos and end up creating files starting with a dash "-"
For example, instead of typing
$touch ./h-ello.txt
if you ended up typing
$touch ./-hello.txt
this would create a file named -hello.txt
Trying to delete a file with a name starting with a dash will cause an error in the bash shell:
$rm -hello.txt
rm: invalid option -- h
Try `rm --help' for more information.
To get around the dash in the filename, use a double-dash "--" before the rm arguments to delete the file starting with a dash.
$rm -- -hello.txt