Pixel Binning: Effect on SNR for Hardware vs. Software Binning
If you have access to the raw pixel data, you can implement binning in software too. They should be identical upto the step-size of the ADC, by which the quantized analog sum of pixels may differ from sum of quantized pixels.

Hardware binning has the advantage that it has to transfer less number of pixels, hence can operate at high fps compared to raw data transfer.