The action "Copy candidate to another position" creates a copy of the candidate's answer to a specific position. Therefore, you can create multiple copies of one answer to multiple positions at the same time. The primary purpose of this function is to assign candidates to current positions from the applicant database, whether they are candidates who were created without a position by sourcing or "recycling" candidates from the talent pool who corresponded to historical positions.
On the other hand, the action "Move candidate to another position" deletes the candidate's answer from the given position and moves it to another position. Its primary purpose is situations where a candidate mistakenly answers, or is mistakenly assigned by a recruiter, to a position that does not match his profile, but you have another position where he fits.
The video shows scenarios of their use in practice.