The information is stored in catalogs. There are users' catalogs, and also some built-in data provided for free by Youlab.Me.
Unlike most other databases, Youlab.Me is specially designed to work with chemical data, including chemical structures, to provide flexible structural search.
If you need to store information about compounds you have at the lab or you would like to sell some chemicals, just create your catalog. This is for free, you will only need to register to do it.
You can take a look at what people have added already, by navigating to Dashboard -> Catalogs in top menu:
You will see your catalogs here too when you create them. Also, other people can share their catalogs with you. Finally, there are public catalogs, which people allow others to see. Companies selling chemicals can make their catalogs accessible to people. There are also a few sample catalogs which we created for you:
The green folder indicates that the catalog is public. A green dollar sign means that the compounds from this catalogs are for sale.