When looking at a black and white scanner the bits relate the the shades of grey supported. The biggest mistake that scanner buyers make when selecting a scanner is to get one with too small optical resolution and too few bits. Most scanner buyers are back in the store within three months buying another scanner with higher capacity in these areas. Make sure you buy a near the top of the line scanner in these areas. Software can always be upgraded more cheaply than hardware.
Scanners often come bundled with software.
Almost all scanners have the image enhancing software of interpolated resolution. Sheet fed scanners and some black and white scanners come with OCR software bundled in. Flat-bed and color scanners often come with image editing software. Many of the software packages are watered down versions of the full-blown commercial version of the software. Be sure that you understand the features of the included software before you upgrade to the full-blown commercial version.