What are the two types of expatriates?

Two types of expatriates are most commonly analyzed in the scientific literature: assigned expatriates (AEs) and self-initiated expatriates (SIEs). 13-Jan-2022

https://www.frontiersin.org/articles/804947#:~:text=Two%20types%20of%20expatriates%20are,%2Dinitiated%20expatriates%20(SIEs).