When it comes to near death experiences specifically, there seems to be two general categories.
One allows for subjective interpretation, such as lights, tunnels, feelings of love, etc.
The other category is very strong objective evidence, as documented by many and described by historian Gary Habermas.
https://www.youtube.com/watch?v=dSW6CPTPG0o
Pim van Lommel, a Dutch cardiologist, has studied NDE for a long time and written about it:
https://en.wikipedia.org/wiki/Pim_van_Lommel