H for Hyperfocal Distance
Its basically, the focusing distance at which both the foreground and background are in focus. Generally, if we keep a fairly deep DOF, while focusing at infinity, almost everything stays in focus. But, if your photo has an object of interest in the foreground, that is comparatively closer to you, then Hyperfocal Distance comes into play. Two ways to do this. One, work out the actual point of focus and use it, else, focus almost one-third into the frame, and it should be fine. Else, go with focus stacking 🙂 Do bear in mind, this needs practice.