Is the "voter" in n-version programming a person or a function in a code?

I've been reading about N-version programming for my reporting in class. From what I learned on the slides, NVP is based on the principle of design diversity, that is coding a software module by different teams ofprogrammers, to have multiple versions.

Is the "voter" a person who judges the algorithm made by different teams or a method/function that chooses the best one that provide better software reliability?

Image here: N-version programming