A variety of high energy ( > 1 keV ) spectra have been observed in recent years from Black Hole ( BH ) and Neutron Star ( NS ) X-ray Binaries ( XB ) .
Some common physical components exist between BHXBs and NSXBs , resulting in some high energy spectral features .
A common component between a BHXB and a weakly magnetized NSXB is the inner accretion disk region extending very close to the surface ( for a NS ) or the horizon ( for a BH ) .
The inner disk radiation can be described by a multi-color blackbody ( MCB ) spectral model .
The surface radiation of the NS can be approximated by a Single Color Blackbody ( SCB ) spectrum .
For a strongly magnetized NSXB , the high energy emission is from its magnetosphere , characterised by a thermal bremsstrahlung ( TB ) spectrum .
In both BHXBs and weakly magnetized NSXBs , a hot electron cloud may exist , producing the hard X-ray power law ( photon index -1.5 to -2.0 ) with thermal cutoff ( 50-200 keV ) .
It has been recently proposed that a converging flow may be formed near the horizon of a BH , producing a softer power law ( photon index about -2.5 ) without cutoff up to several hundred keV .
Based on these concepts we also discuss possible ways to distinguish between BH and NS XBs .
Finally we discuss briefly spectral state transitions in both BH and NS XBs .