Stamps.com is an online service that allows users to print postage for mailing and shipping packages directly from their computers. It provides access to various shipping options, including USPS and UPS, making it convenient for both personal and business use. Users can manage their shipping needs without having to visit a post office. The platform offers features like tracking shipments, scheduling pickups, and managing shipping labels. It is designed to save time and streamline the shipping process, catering to small businesses, e-commerce sellers, and individuals who frequently send mail or packages.