Which meaning of the root alter define the word alternate as in this sentence?

The root "alter" comes from the Latin, which literally means "other"; then through French influence, probably from the times when the Norman invasion to England was occurring, it settled as alteration, referring to the process of changing, being changed , modified, or as the difference derived through changes. Hence "alternate" conveys reciprocity, in the sense of interchanging each other's places one after another, or basically "every other".

the italian poet francesco petrarch did! (:

what’s your question?