Monopsony describes a market where one buyer faces many sellers.
Because the buyer is the sole purchaser, it may have market power over the price or terms it offers. The standard textbook example is a single major employer in a local labor market, although real-world markets can have several buyers and still display monopsonistic power.
Monopsony is the buyer-side counterpart to monopoly, where one seller faces many buyers. Oligopsony describes a market with a small number of powerful buyers rather than only one. These labels concern the number and influence of buyers, not whether the product itself is identical.
In labor economics, monopsony can allow an employer to pay wages below the level that would prevail in a competitive market and employ fewer workers, depending on the model and market conditions.