collaborative story-lines: PC control
Guide never direct or force PC actions.
RPGs more like a collaborative or shared story where the DM sets the stage, the lights, the antagonists, and the general plotlines. When it comes to PC action, the acting and motivations are improvisational.
That said I think if the DM spent lots of time on adventure and preparation players should respect that. Sandbox games could work, I suppose, but I haven't seen them. When I don't "railroad" my players, they tend to fart around.