  We present timing and time-integrated spectral analysis of 127 bursts from
SGR J1935+2154. These bursts were observed with the Gamma-ray Burst Monitor on
the Fermi Gamma-ray Space Telescope and the Burst Alert Telescope on the Neil
Gehrels Swift Observatory during the source's four active episodes from 2014 to
2016. This activation frequency makes SGR J1935+2154 the most burst prolific
transient magnetar. We find the average duration of all the detected bursts to
be much shorter than the typical, anticipated value. We fit the burst
time-integrated spectra with two black-body functions, a Comptonized model and
three other simpler models. Bursts from SGR J1935+2154 exhibit similar spectral
properties to other magnetars, with the exception of the power law index from
the Comptonized model, which correlates with burst fluence. We find that the
durations and both black-body temperatures of the bursts have significantly
evolved across the four active episodes. We also find that the burst time
history exhibits two trends, which are strongly correlated with the decay of
the persistent emission in each outburst.

High Energy Astrophysical Phenomena