Why is apple called a false fruit? Which part$(s)$ of the flower forms the fruit?

(N/A) Fruits derived from the ovary and other accessory floral parts are called false fruits.
On the contrary,true fruits are those fruits which develop from the ovary,but do not consist of the thalamus or any other floral part.
In an apple,the fleshy receptacle (thalamus) forms the main edible part of the fruit.
Since the fruit develops from the thalamus instead of just the ovary,it is classified as a false fruit.