The Farm Collie is a herding dog of collie type. There can be many definitions for 'Farm Collie';
1) any collie-like dog that works on farms,
2) any collie-like dog that does farm work such as herding, guarding etc,
3) A dog of the Scotch Collie type that works livestock in a loose-eyed style.
4) The remnants of the original Scotch Collie that lived and worked on farms in America from which the Australian Shepherd and English Shepherd breeds derived.
5) A Rough Collie of old fashioned looks that does not meet current interpretations of breed standards.
Here all the discussion is about the remnants of the original Scotch Collie (No.4).