Binning
Binning is the term used to describe the technique of combining the output of adjacent pixels on a sensor. This can be performed on pixels in a single axis or, more commonly, in both directions. It will usually be shown as "2x horizontal binning" or "4x4 binning" where the numbers show the size of the cluster of pixels that is combined. This technique has a detrimental effect on the spatial resolution, but increases sensitivity, speeds up frame rates and increases the signal-to-noise ratio (SNR) .