Try It in the Console
Open DevTools (F12) > Console tab. Type each line and observe:
let name = "Your Name";
typeof name
let age = 20;
`Hello, ${name}! You are ${age} years old.`
"5" + 3
"5" - 3
function double(x) { return x * 2; }
double(21)
Why did "5" + 3 and "5" - 3 give different results?