//Function declarations load
//before any code is executed
//while
//Function expressions load
//only when the interpreter reaches that line of code.
//eg.
add(1,2);
function add(a,b){ //this is a function declaration
return a+b;
}
sum(1,5); //this is a function expression will throw initialization error
const sum = () => a+b; //function expression is strored in variable
function nameOfFunction() {
//some code here....
}