ASP.NET Page Directives : Directory Structure « ASP.Net Instroduction « ASP.NET Tutorial

You can control the behavior of your ASP.NET pages by using these directives. 

Here's an example of the Page directive: 

<%@ Page Language="VB" AutoEventWireup="false" CodeFile="Default.aspx.vb"
    Inherits="_Default" %>

Directives are commands that the compiler uses when the page is compiled. 

Directives are simple to incorporate into your pages. 

A directive is written in the following format:

<%@ [Directive] [Attribute=Value] %>

You can add more than a single attribute to your directive statements: 

<%@ [Directive] [Attribute=Value] [Attribute=Value] %>

1.2.Directory Structure
1.2.1.Application Directory Structure
1.2.2.ASP.NET Application Folders
1.2.3.ASP.NET Page Directives
1.2.4.directives in ASP.NET
1.2.5.@Page directive
1.2.6.Page Directives, code section and layout