Fill (archaeology) in the context of "Cut (archaeology)"

In archaeology and archaeological stratification, a cut or truncation is a context that represents a moment in time when other archaeological deposits were removed for the creation of some feature, such as a ditch or pit. In layman's terms, a cut can be thought of as a hole that was dug in the past, though cut also applies to other parts of the archaeological record such as horizontal truncations like terraced ground. A cut context is sometimes referred to as a "negative context", as opposed to a "positive context". The term denotes that a cut has removed material from the archaeological record or natural at the time of its creation, as opposed to a positive context, which adds material to the archaeological record. A cut has zero thickness and no material properties of its own and is defined by the limits of other contexts. Cuts are seen in the record by virtue of the difference between the material it was cut through and the material that back-fills it. This difference is seen as an "edge" by the archaeologists on site. This is shown in the picture (Fig. 1), where a half sectioned Saxon pit has had half its backfill removed and we can clearly see a difference between the ground the pit was cut into, and the material originally filling the pit. Sometimes these differences are not clear and an archaeologist must rely on experience and insight to discover cuts.