Residue is material remaining after an event, use or treatment. The word describes what remains, not what it is made of.
What this means at your property
Fire residue, dried cleaning product and mineral deposits can appear on the same kinds of surfaces but require different assessment. A successful method for one residue should not be assumed suitable for another.
What information helps choose a cleaning approach?
Identify the event, surface material and previous treatments. Ask whether a test area is appropriate and how damage to the finish will be distinguished from removable residue before authorizing treatment across the whole area.