'\n' = \n
"\n" = new-line
there's also \t, \r, \0, etc.
The difference between single and double is static vs dynamic strings
For example try:
Code:
$bob = 'hi it\'s me';
echo "$bob";
$bob = "hi it's me";
echo "\$bob";
$bob = "hi it's me";
echo '$bob';
That will hopefully explain it a bit.