All Apple products have a model number. It is normally on the back of the product and for older Apple devices may be called "Family Number". It is normally a letter followed by 4 or 5 numbers although modern formats may be a mix and end in '/A'. In some cases the model number may relate to a few products or a few different specifications of an Apple device.
Apple model number :
Click herefor an idea of what this Apple device may be worth