What is the difference between using echo and return in a PHP function?

The main difference between using echo and return in a PHP function is that echo is used to output data to the screen, while return is used to return a value from a function. If you want to display something directly to the screen within a function, you should use echo. However, if you want to pass a value back to the calling code, you should use return.

// Using echo to output data directly to the screen
function displayMessage() {
    echo "Hello World!";
}

displayMessage();

// Using return to pass a value back to the calling code
function getSum($num1, $num2) {
    $sum = $num1 + $num2;
    return $sum;
}

$total = getSum(5, 3);
echo $total;