Why does my code work? :)))

correctguess = 0;
var question1 = prompt("Where does the footballer Cristiano ronaldo play?");
question1 = question1.toUpperCase();
if (question1 === "JUVENTUS") {
  correctguess += 1;
}


var question2 = prompt("How old is Jorge Masivdal?");
question2 = question2.toUpperCase();
if (question2 === "34") {
  correctguess += 1;
}

var question3 = prompt("In which country is located the city Venezia?");
question3 = question3.toUpperCase();
if (question3 === "ITALY") {
  correctguess += 1;
}


var question4 = prompt("Who is the main protagonist in the video game The Witcher?");
question4 = question4.toUpperCase();
if (question4 === "GERALT OF RIVIA") {
  correctguess += 1;
}


var question5 = prompt("What does A.I stand for?");
question5 = question5.toUpperCase();
if (question5 === "ARTIFICIAL INTELLIGENCE") {
  correctguess += 1;
}

document.write("You got " + parseInt(correctguess) + " out of 5.  ");

if (parseInt(correctguess) === 5 ) {
  document.write("You won a gooooold medal.")
} else if (parseInt(correctguess) === 4 || parseInt(correctguess) === 3) {
  document.write("You won a silver medal.");
} else if (parseInt(correctguess) === 2 || parseInt(correctguess) === 1) {
  document.write("You won a bronze medal.")
} else {
  document.write("You get no medal.")
}