Band pass filter , circuit analysis
This configuration is an active inverting bandpass filter. Simply said, low frequencies are blocked by capacitor C1 while capacitor C2 enables high frequencies to pass through untouched. Both cutoff frequencies (frequency at which the amplitude reaches -3dB) are adjustable independently. 

Low pass filter cutoff frequency is set by R2 and C2.

\begin{equation}
f_L = \frac{1}{2 \pi R_2 C_2}
\end{equation}

High pass filter cutoff frequency is set by R1 and C1

\begin{equation}
f_H = \frac{1}{2 \pi R_1 C_1}
\end{equation}

Setting \$ f_H &lt; f_L \$, pass-band voltage gain is approximated by resistor ratio.

\begin{equation}
A_v \approx \frac{-R_2}{R_1}
\end{equation}

A square wave passed through this filter will be a sum of sine waves. All frequencies in the pass-band will be kept untouched, while other will see their amplitude reduced and phase altered.