Point-of-sale. POS involves two things - a physical way to read cards and a software that knows what to do with them. This means you can run a retail store in conjunction with your online one, or simply let people buy right away at sample sales, markets and trade fairs. Your software can come from Shopify’s POS and card reader or from others like Stripe and Square. Check out more information about offering a physical point-of-sale here.