A ledger board, when installing cabinets, serves as a vital support structure, especially when hanging wall cabinets. It's a horizontal board secured to the wall studs, providing a secure, level mounting surface. By attaching cabinets to the ledger, you ensure they're aligned and evenly distributed, bearing the weight safely. This method simplifies installation, enabling solo work and maintaining accuracy. Remember, the ledger must be perfectly level and firmly anchored to handle the cabinet load, enhancing the stability and longevity of your cabinet setup.