Printers paper trays are compartments within a printer that hold and store paper for printing. They are often located at the bottom or front of the printer and can hold varying capacities of paper, depending on the model. Paper trays are designed to keep the paper organized, prevent paper jams, and allow for easy loading and unloading of paper. Some printers may have multiple paper trays, allowing users to load different sizes or types of paper simultaneously. Additionally, some paper trays may have adjustable guides or settings to accommodate different paper sizes or orientations.