What is scionwood?

Scionwood, or scions, are the small branches you graft with in order to propagate a variety. It is the one year growth from a tree. The scionwood is what grows into the desired variety when we are grafting! For example, if you want to grow a Pink Pearl apple tree you would collect scionwood from a Pink Pearl tree and graft it onto rootstock. 

Scionwood and budwood are essentially the exact same thing, it's just a difference in time of year that they are collected/used and handling.