Business-to-business (or B2B) is a commercial transaction that occurs between two businesses or companies.One of the most common examples of B2B is when a company outsources its products' resources and production to a manufacturing company.In Ecommerce, B2B occurs when an online business, retailer, or service provider outsources its operations to a third-party provider like BPO call center companies, packing and shipping companies, or Ecommerce service providers.KDCI Outsourcing, for example, is a B2B outsourcing company that provides services to other businesses that need help with all things design, marketing, Ecommerce, and more.