PosCow is a service designed to enhance the e-commerce capabilities of Squarespace stores by enabling international checkout. It allows businesses to provide global shopping experiences by integrating features such as instant international shipping quotes, automatic tax, VAT, and GST calculations, and a seamless checkout process. This service is primarily aimed at US-based businesses that sell tangible goods and wish to expand their market reach by accepting international customers without the complexities typically associated with cross-border sales.