Spinets are small upright pianos that were popular in the mid-20th century. They are characterized by their short strings and small size, making them ideal for small spaces. The term 'SPINET' is derived from the Italian word 'spina, ' meaning 'THORN, ' referring to the shape of the instrument's frame. Spinets are still manufactured today, although they have become less popular due to the introduction of digital pianos.