The term 'deck coating' refers to a type of SEALER used to protect outdoor decks from the elements. A SEALER is a liquid or paste that is applied to the surface of the deck to create a protective barrier against moisture, dirt, and other environmental factors. Sealers are typically made from acrylic, polyurethane, or epoxy, and can be applied with a brush, roller, or sprayer. The SEALER helps to prevent the wood from warping, cracking, and fading due to exposure to the elements.