Considering entropy (S) as a thermodynamic parameter, the criterion for the spontaneity of any process is
$\Delta {S_{system}} + \Delta {S_{surroundings}} > 0$
$\Delta {S_{system}} - \Delta {S_{surroundings}} > 0$
$\Delta {S_{system}} > 0\,\,\,$only
$\Delta {S_{surroundings}} > 0$ only
