Depends on ripeness
Mature, "dry" coconuts have high fat content, a crunchy white pulp that can be made into coconut milk.
It is abundant in medium-chain fatty acids. Young green "water" coconuts have a transparent, sweet jelly pulp and less fat, and a sterile liquid with electrolytes
of similar concentration to human blood. This was used to rehydrate
some soldiers during ww2 in the pacific, by intravenous infusion!
Answer assisted by Jin Packard, Medical Student