Raw data refers to “plain facts”. What are plain facts?
Let us use some examples. The pixel values from a CCD (charged couple device) at a particular moment is data.
The events of a computer mouse, such as movements and states of buttons (pressed or not), are data.
The log of activities of a particular credit card is data.
The answer of a multiple choice question in an online test is data.
Data is easy to capture, and there is no or little processing before data is transduced to a form that can be stored (in a computer, a pile of paper, magnetic tape or other means of storing data).
Data does not only apply to computers. Humans also acquire a huge amount of data. The signal from each cone or rod cell on the retina is data. The signal from each taste bud is data. The signal from each hair in the inner ear is data.
Despite the vast amount of data that our nerves collect, it does not make a human (or any living organism) intelligent.