What are some differences between error and exception in PHP?
<p>I'm a beginner in PHP. So far, from the source I'm learning from, the only mechanism to trigger an exception is by writing a line that throws it.</p>

<p><code>throw new Exception('message')</code></p>

<p>Furthermore, on the code below, any exception won't be thrown, but an error will be raised.</p>

<pre><code>try
{
    $file = fopen('no such file.txt', 'r');
}
catch(Exception $e)
{
    echo 'Exception: ' . $e-&gt;getMessage();
}
</code></pre>

<p>Please give me some explanations. 
It seems this try..catch block is not so useful in PHP, unlike in Java or .NET. </p>
