There is an unseen world in small details waiting to be discovered. Going close and photographing these small details is what makes macro photography special. There are different definitions for macro photography. Macro photography is generally termed as photographs that are taken at close proximity to the subject in a manner that the scene in front of the lens being captured is of the same size as the sensor. The lens has to focus really close for this.
(Flower bud photographed with Sigma 105mm macro EX DG lens mounted on a Nikon D200 body, f/8, 1/250 sec at ISO 100)