B2B- Business to Business.
Here you sell your services/products to a business and not to end customers.
Profit margins are low .
Quantity is more.
Deadstock problem is less.
Deadstock for one person will be new for another. You buy bulk of similar products.
B2C- Business to Customer
Here you sell your services/products to end customers.
Direct contact with end customers.
Profit margins are high.
Quantity sold is less compared to B2B.
Deadstock is a big problem.
To keep attracting customers, you need to keep investing and adding new and fresh products. You buy smaller quantity but larger variety.