Present is the time that is perceived directly, not as a recollection or a speculation.  The idea of present cannot be separated from a position in space.  That is, the present is a point in space-time.

When comparing time in places separated by great distances, the notion of present becomes unclear.  E.g. we see stars such as they have been many years ago, because light takes so much time to travel. 

See also: past, future