An import quota is a limit on the quantity of a good that can be produced abroad and sold domestically.
Because the quota raises the domestic price above the world price, domestic buyers of the good are worse off, and domestic sellers of the good are better off.
License holders are better off because they make a profit from buying at the world price and selling at the higher domestic price.
With a quota, total surplus in the market decreases by an amount referred to as a deadweight loss.
The quota can potentially cause an even larger deadweight loss, if a mechanism such as lobbying is employed to allocate the import licenses.