  We study the spectral and temporal characteristics of the source GS
2023$+$338 (V404 Cyg) during the initial phase of its June 2015 outburst, over
the energy range of 0.5 - 150 keV. This is the first detailed study of the
characteristics of this source based on {\it SWIFT} observations, being
reported. Based on our analysis, we understand that the source existed in the
hard, intermediate and soft spectral states. We find that the evolution of the
spectral parameters, the hardness intensity diagram and the rms-intensity
diagram are not similar to those observed for most of the outbursting black
hole sources. We also observe presence of weak peaked components in the power
density spectra during the intermediate state of the source. Dramatic changes
in the spectral and temporal properties are also exhibited before the ejection
of a radio jet suggesting it to be associated with the coronal mass ejection.
It seems that may be due to evacuation of the inner part of the Keplerian disc
for a short duration, the disc component is not observed after the huge radio
flare. The absorption features observed in the low energy spectra suggest the
presence of wind emission and the evolution of the characteristics of the
variable Fe line emission during both hard and intermediate states, indicate
its origin to be probably related to the wind/outflow.
