Complex sentence: Contexts are single events or actions that leave discreet detectable traces in the archaeological sequence or stratigraphy, these can be deposits such as the back-fill of a ditch, structures such as walls and "zero thickness surfaciques" better know as "cuts".
Split into simpler sentences: Contexts are single events or actions that leave discreet, detectable traces in the archaeological sequence or stratigraphy. They can be deposits (such as the back-fill of a ditch), structures (such as walls), or "zero thickness surfaciques," better known as "cuts".