it is an inverse move, moving file "bar" to file "foo"

it moves the files "-i" and "foo" to the directory "bar"

it moves the file "foo" to file "bar", provided that no such file "bar" currently exists. If there is a"bar" file then the move command interactively asks the user whether "bar" should be overwritten.

it moves the file "-i" to two separate but identical files, named "foo" and "bar"