  The gravitational waves were detected directly for the first time on
September 14, 2015 by two LIGO detectors at Livingston, Louisiana and Hanford,
Washington, USA. Careful analysis revealed that this signal was produced by the
last moment of inspiral and merger of two black holes that have been orbiting
each other. Since the first detection, several other gravitational wave
sources, including one neutron star merger event in August 201,7 have been
observed by the LIGO together with Virgo. This article provides a very brief
overview of the history toward the understanding the nature of gravitational
waves, detectors, types of sources and achievements of the gravitational wave
detectors. We then discuss astrophysical implications of the recent detections
of black hole and neutron star binaries and provide short term and long term
prospects of gravitational wave astronomy.
