Because it is made from peanuts but has the consistency of butter.
Its got the same consistancy of butter, but its made of peanuts.
I've never seen peanut butter with butter in it. So it might be possible, but it would have to be pretty rare.
No. Peanut butter is, at its most basic, ground peanuts (sugar or salt is sometimes added). The consistency, creamy and suggestive of butter, is actually due to the peanut solids being in suspension...
They are both creamy.....