@ symbol in PHP

What is the @ symbol in PHP.

I see it used in var assigning like this:

$myvar = @file(blahblah);
$myvar = @somefunction();
and other stuff.

All I can learn after a bunch of reading is that it has to do with resource type.
But @ isnt google searchable, and I just randomly see it in sourcecode all over the place.

:-o help :-o