Fixed income Reinvestment risks referring, because, interest, therefore

Jupiter

When the book talks about the "interest rate" in the book under reinvestment risk are they referring to coupon rate as the interest rate ?
Companies call their bond when interest rate falls. They are referring to coupon rate here right? because they would be able to reissue bond at a lower coupon, therefore less coupon/interest payment for the company.

Please clarify this for me thank you.