B2B ( Business to Business) is a very common term used in the travel industry to refer travel agent network who use login given by different suppliers ( Amadeus, Galileo, GTA, Miki, Rooms XML etc.) or Travel Agencies ( Yatra, Cleartrip, Coxs&Kings, Via.com, Akbar Travels, etc.). So B2B is a Travel Agent who are selling tickets/ itinerary etc. by purchasing from different suppliers.
Note- B2B do not have their own inventory, they purchase from different suppliers & sell further.
To Grow Business or earn more profit B2B has the following options –
B2B2B ( B2B2Business or Business to Business to Business) is a sub-agent for B2B agents. Here B2B can grow their business by giving their login in the market to different agents ( or subagents) to sell their inventory. B2B can also add a markup on those inventories to earn profits.
B2B2C ( B2B2Customer or Business to Business to Customer) is a website for B2B agents. Here all the direct customers can visit & search & book & pay online using multiple payment options. its a white label website for B2B agent.