Why B2B website needed?

Short for business-to-business. The electronic exchange of products and services between businesses without the direct involvement of consumers. B2B’s effects on business include streamlining purchasing, accounting, and other administrative functions; lowering transaction costs; and simplifying the sale of excess inventory. Related businesses have collaborated on the creation of Internet-based supply-chain networks. 

B2c:The direct electronic exchange of products and services between businesses and consumers. B2C’s effects on business include improving the efficiency in delivering goods and services to consumers.