Quince (Cydonia oblonga) belongs to the same family as apples and pears. It has a shape that's similar to a pear, but larger. It has lumpy yellow skin and its hard flesh is quite bitter so it shouldn't be eaten raw.
When fully ripe, the quince has a wonderful perfume. It can be added to cooked apple and pear dishes or used to make quince sauce, and it makes excellent preserves, especially marmalade. Quince paste or 'membrillo' is a popular accompaniment to cheese in Spain.