function Calc(x,y) { z = x + y; return z; } || function Calc(4,5); & document.write ( functionCalc(4,5) ); Are these two same?

Question

Please tell me, As I mentioned, isn't there any different between those two function calling types? Then why they mention those two types in the lesson?

Answer 1

The document.write version actually displays the result on the webpage, while the first version doesn't, only calculates it but discards of it right after.