What is incremental DOM? How is it different from virtual DOM?

Incremental DOM is used internally at Google, and it is defined by this key idea:

Every component gets compiled into a series of instructions. These instructions create DOM trees and update them in-place when the data changes.

React was the first mainstream framework to use virtual DOM, which is defined by this key idea:

Every component creates a new virtual DOM tree every time it gets rerendered. React compares the new virtual DOM tree with the old one and then applies a series of transformations to the browser DOM to match the new virtual DOM tree.