Dehumidification is the removal of water vapor from air. It is one part of managing moisture during structural drying.
What this means at your property
Wet materials can release moisture into a room after standing water has been extracted. If that vapor remains, drying conditions can deteriorate. A drying plan considers moisture removal, airflow and temperature together rather than treating room humidity as the only measurement.
How do you know the work is progressing?
Ask for readings from affected materials as well as the surrounding air. Falling humidity is useful information, but it does not by itself prove that a concealed wall, floor or cabinet is dry.