Apples would be a fruit. Apples and oranges would be fruits, as in fruits and vegetables.

"fruit (countable and uncountable; plural fruits) (see Usage notes for discussion of plural) 1. (botany) The seed-bearing part of a plant, often edible, colourful/colorful and fragrant, produced from a floral ovary after fertilization. While cucumber is technically a fruit, one would not usually use it to make jam. 2. Any sweet, edible part of a plant that resembles seed-bearing fruit, even if it does not develop from a floral ovary; also used in a technically imprecise sense for some sweet or sweetish vegetables, such as rhubarb, that resemble a true fruit or are used in cookery as if they were a fruit. Fruit salad is a simple way of making fruits into a dessert. 3. A positive end result or reward of labour or effort. His long nights in the office eventually bore fruit, when his business boomed and he was given a raise. 4. Offspring from a sexual union. The litter was the fruit of the union between our whippet and their terrier. 5. (slang, offensive) A homosexual or effeminate man. Usage notes: - In the botanical and figurative senses, fruit is a singular noun and also used as a collective noun. a bowl of fruit; eat plenty of fruit; the tree provides fruit. - Fruits is also sometimes used as the plural in the botanical sense. berries, achenes, and nuts are all fruits; the fruits of this plant split into two parts. - When fruit is used as a collective noun in the botanical sense, a piece of fruit is often used as the corresponding singular form. - In senses other than the botanical or figurative ones derived from the botanical sense, the plural is fruits." Source and further information: http://en.wiktionary.org/wiki/fruit#Noun