While determining where a trace curve/gel image has a peak/band we define which data
points belong to a local maximum.
In other words:
We throw all these data points/pixel into a kind of bin and, then, term the bin 'peak' or 'band'.
Finally, we glue a label with positional information on the bin.
This procedure is similar to throwing paper balls according to their size into different paper
bins that have labels 'balls with about 50 mm diameter', 'balls with about 60 mm diameter' etc.
This procedure is called 'binning'.
A bin has a certain size (paper balls with diameter from ... to ...) and holds data points
(number of paper balls with a certain diameter).