Difference between echo '...' and echo "..."

Question

What is Difference between echo '...' and echo ".." ?

Answer 1

supriya🍀
i tried this in codeplayground. it showed different output. how could i get same output?

<?php
$a = 4;
$b = 5;
$c = $a+$b;
echo '$c';
echo "$c";
?>

Answer 2

Vc fala portugues tambem