I often get asked what the difference is between a cushion insert and a pillow form. On our website we list both, which sometimes causes confusion to potential customer who are unsure what to purchase. The simple answer is that they are exactly the same thing - i.e. they are synonyms.
The reason we list both is that peope seem to know either one term or the other so we want to make sure that potential customers know what product we are selling. Other variations include cushion forms and pillow inserts, again all amounting to the same product.