.

In this regard, which way does a headstone face?

In most Christian burials the headstone will be placed at the head of the individual interred. The grave will be situated with the head of the individual to the west and their feet will be to the east. If they were to be stood up while in the grave, they would be looking and facing east.

Likewise, why are people buried facing east? well in traditional Christian burial, the graves face east, because it is a reminder of the second coming of Christ, since he's supposed to appear in Jerusalem, which is eastward from the countries ( if you're talking of Europe, or America's that is) and when Christ comes, his People will rise, and most Christians

Keeping this in consideration, why do graves face the same direction?

Today in North America the convention is for the graves to face East with the Head west and the feet East. The stone then also faces East. This was attributed to the custom of not wanting to stand on the body while reading the stone inscription (but you would likely be standing on someone else).

Why do some graves face north and south?

The above-ground crypts at this Catholic cemetery face north-south instead of the usual east-west. Positioning graves this way actually started as a pagan ritual, so the dead would face the rising sun, but it continued through years based on the biblical claim that the second coming of Christ would be from the east.