I think el realtaed site and authentic site is a different. EfL site introduce about english ir leraning english which country did not use english own their L1. Also EFL sute transform a lot of imformation about english. Forinstance, when i want to know about foreign country news, ther are many efl site wirtting or post about english news. I search that i got imformation what i want.  authentic site is i think trust site. Because this site, there are no vrius in the site. Also authentic site very useful when i want to imformation. When i need information,  i used daum or naver.