While designing the data model for a project, we need to represent every physical entity with an online analog. Like for consumers of your products/services, we have Customer.
Here Customer is not just a word in online world. Rather it is an item type, which has its own attributes and data structure, like email, mobile of customer. every thing related to customer will go in a table called Customer.
Similarly, we need to define an online entity to represent the whole business house. This will have all the attributes, related to business, like websites associated with it, all physical stores the product catalogs, currency it operates in, etc.
This entity chosen is Base store.