aspx.cs need explain to me
<pre><code>using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;

public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {

    }
}
</code></pre>

<p>and some1 explain it to me what do all this usings do please?</p>

<p>im really struggling to find anything on the internet 
thanks</p>
