The definition of self are tremendous and depends from person to person. I believe it has no constant defintion until in this contemporary time. Because we came from different cultures and places your view of the self can't be exactly the same of the self of the other. The article was very informative that it started talking about the different definition of self from different schools from socrates to churchland.

https://buddingpsychologists.org/the-self-in-modern-psychology/