I would disagree with Joseph's definition that 'data' are defined as a set of individual pieces of 'information'. For example, the North American Datum of 1927 has its initial point at Meades Ranch in the state of Kansas. From this known point all other points can be determined horizontally on the ellipsoidal surface using azimuth's and distances among other paramaters. There are some subtleties being missed here. Thus 'data' was just the plural of 'datum'.
Statistics are a wonderful discipline.