B2B stands for Business to Business, which refers to business transactions between companies、If you're referring to an online platform or website that facilitates these types of trade, like Alibaba, Global Sources, or MadeinChina, those are all examples of B2B platforms in the外贸 (foreign trade) sector.

If you have any specific questions about how to use these platforms, what services they offer, or any other related queries, feel free to ask!