B2B = Business-To-Business
B2B is the purchasing interaction between businesses. The seller is a business; the buyer is a business. This interaction is commonly represented between different manufacturers; manufacturers and wholesalers; wholesalers and retailers; retailers and business customers.
Goods are usually purchased in large quantities and later resold either on their own or in another product form (i.e. flour is bought in large quantities for a baker to then make bread and sell to the public or cafes).
B2C = Business-To-Consumer
B2C is the purchasing interaction between retailers and [public] customers. Customers are generally individuals who might only purchase one item. B2C more recently refers to online retailing, labelled ‘e-tailing’ (electronic retailing). It includes the revenue produced from selling goods or services via advertising or subscription systems (e-newsletters; YouTube subscribers).