What does it mean to add cleaning fluid?

[VonRosalie]

Adding cleaning fluid refers to the need to replenish the windshield washer fluid when it runs out. Windshield washer fluid is a consumable item in vehicle use, and some car models can detect the remaining level of the washer fluid. When the windshield washer fluid is depleted, the vehicle will alert the owner to add more promptly to avoid affecting normal usage. Windshield washer fluid is primarily composed of water, alcohol, ethylene glycol, corrosion inhibitors, and various surfactants. When the transparency of the front windshield decreases, spraying some washer fluid can provide a clear and bright view. During nighttime driving, dust on the windshield can scatter light, so spraying washer fluid helps maintain the windshield in optimal transparency.