What do these lines mean?
<p>Sorry for the very vague question, but I'm not really sure how to Google/ask this.</p>

<p>Basically, I've seen these 2 (similar) lines in a lot of c# code:</p>

<pre><code>[DllImport("user32.dll")]
</code></pre>

<p>and</p>

<pre><code>Task&lt;string&gt; getStringTask = client.GetStringAsync("http://msdn.microsoft.com");
</code></pre>

<p>In the first snippet, what is it actually doing. What are the <code>[ ]</code> used for?</p>

<p>In the second snippet, what is the <code>&lt;string&gt;</code> declaration called so I can find more information on it.</p>

<p>Thanks!</p>
