Business-to-consumer (B2C) transaction refers to businesses dealing with individual consumers or end customers. Such as web shops and Teleshopping. Example is www.amazon.com
Consumer-to-consumer (C2C) is a type of business model that facilitates interaction between customers. It is an online platform where anyone can put products on sale without any middleman, to be bought by any end consumer. The best example of c2c e-commerce is Ebay.com.