High intensity, ultrashort light pulses can excite matter to high temperature at high density. This feature of ultrashort pulses provides a great opportunity for doing experiments in the lab that help us understand the behaviour of matter pushed to extreme conditions. Research in this area bridges diverse areas - from astrophysics to accelerator physics and from condensed matter physics to biology. This talk will introduce the subject and dwell on two basic themes - one dealing with how light couples to such plasmas and another that deals with the consequence of such coupling, namely the production and behaviour of 'hot' electrons (ranging up to MeV). I will present some results of experiments performed at TIFR - creation of gigantic magnetic fields, ultrafast plasma dynamics, passage of relativistic particles through dense, hot matter and interesting consequences in terms of electron and ion acceleration, ultrafast hard x-ray emission, laser fusion and laboratory astrophysics etc..