  Statistically, the cool loop's footpoints are diagnosed using Si~{\sc iv}
resonance lines observations provided by Interface Region Imaging Spectrograph
(IRIS). The intensity and Full Width at Half Maximum (FWHM) of the loop's
footpoints in $\beta${--}$\gamma$ active regions (ARs) are higher than the
corresponding parameters of footpoints in $\beta$ ARs. However, the Doppler
velocity of footpoints in both ARs are almost similar to each other. The
intensities of footpoints from $\beta${--}$\gamma$ AR is found to be around 9
times that of $\beta$ AR when both ARs are observed nearly at the same time.
The same intensity difference reduces nearly to half (4 times) when considering
all ARs observed over 9 years. Hence, the instrument degradation affects
comparative intensity analysis. We find that Doppler velocity and FWHM are
well-correlated while peak intensity is neither correlated with Doppler
velocity nor FWHM. The loop's footpoints in $\beta$-$\gamma$ ARs have around
four times more complex Si~{\sc iv} spectral profiles than that of $\beta$ ARs.
The intensity ratios (Si~{\sc iv} 1393.78~{\AA}/1402.77~{\AA}) of the
significant locations of footpoints differ, marginally, (i.e., either less than
1.9 or greater than 2.10) from the theoretical ratio of 2, i.e., 52\% (55\%)
locations in $\beta$ ($\beta${--}$\gamma$) ARs significantly deviate from 2.
Hence, we say that more than half of the footpoint locations are either
affected by the opacity or resonance scattering. We conclude that the nature
and attributes of the footpoints of the cool loops in $\beta$-$\gamma$ ARs are
significantly different from those in $\beta$ ARs.
