Definitions of tying product
a product which when bought from a seller, the seller then requires the buyer to buy a second product from the same seller (=the tied product). This is the situation in a tying agreement, which is when someone buying one product from a seller must buy a second product (or must not buy the tied product from a different seller).
This may limit consumer choice for buyers wanting to purchase one tying product by forcing them to also buy a second tied product as well.