Sometimes you need to guide your filament from the spool to a printer on the other end of the room. You want to keep out moisture and dust, utilize the same fittings you already have to secure the ends, and you don't want Bowden tubing because its small internal diameter will cause more friction over these extreme lengths. You need a Filament Guide, also known as a Reverse Bowden.

A Bowden tube is a tube from the extruder to the hotend. A Reverse Bowden, on the other hand, goes from the spool to the extruder. Oftentimes pros will keep their filament in a "Dry Box" (which can be anything from a simple tupperware container to a food dehydrator.) and run a Filament Guide or Reverse Bowden from the Dry Box to the printer.