What does it means to enable WAPI?

none asked me to enable wapi. Here is the complete question. J live in china and j bought several iPhone in China and in Europe. J always checked one difference in the software section about WIFI. Europe/USA has the "WIFI" while China has the "WLAN". Two months ago j bought an iPhone XR by official Chinese apple store. Few days ago, j noted that, in the WIFI section, there is one selection to enable the WAPI then j'd like to know what practically means, to enable or not, the WAPI. J don't want to know more than a simple basic knowledge of it and what is your suggestion about. Thank you

First of all, sincerely thanks for your reply. With the help of a friend j could read the link you sent but , being not an expert j couldn't understand well what to do. Practically j couldn't solve my original question: being in China now, enable or not WAPI? if j can exploit furthermore your time, j'd like to receive your suggestion but, in any case, j renew the thanks for your answer