What is the major difference between biosimilar and interchangeable biological products?

A biosimilar product can be prescribed by a health care provider in place of the FDA-approved reference product. The health care professional has to write the specific name of the product on the prescription if they want to prescribe the biosimilar.

An interchangeable biological product may be substituted for the reference product by a pharmacist without the intervention of the health care provider who prescribed the reference product. That means the patient may receive the interchangeable instead of the reference product, even if the health care provider writes the prescription for the reference product.

In other word, if the biological products are interchangeable means it is an interchangeable biological products then patients who brings the prescription of the reference molecule, can receive / substituted with the  the interchangeable biological products. In case of biosimilar healthcare prescription mentioning biosimilar brand name is mandatory.