What is contact cleaner used for?

A contact cleaner (also called electrical cleaner, switch cleaner, electrical contact cleaner, and specific for automotive repair, battery terminal cleaner) is a solvent cleaner designed to remove contamination from electrical contacts, the conductive surfaces of connectors, switches and other electrical and electronic components with moving surface contacts. The goal is to quickly remove insulative contamination as quickly as possible, avoiding a lot of wiping and scrubbing if possible. Contact cleaning solvents are usually come in pressurized aerosol packaging for convenience and to provide a forceful spray that creates agitation and reaches into all the crevices of the connectors.