What’s important to note is that Alibaba’s platforms merely facilitate the transactions. They manage the marketplace and charge a small commission, but don’t hold – or sell – any merchandise themselves.
Amazon, by comparison, plays in both markets. On Amazon.com, you’ll find thousands of products you can by directly from 3rd party businesses. But Amazon is also in the business of stocking items and selling products directly to consumers. In many instances, they’re competing directly with the same merchants who are using their platform to sell.
Both companies have other business arms. Each has a cloud computing division (although Amazon’s is much bigger), both are involved with media creation and Alibaba even owns a stake in a professional Chinese soccer team!
But the marketplaces where they sell products are the bread-and-butter of each one’s business.