First of all there are Three Type of Control use in master Page:
- Content Place Holder : Content placeholder controls indicate regions of replaceable content on the master page. They appear in Code view as <asp:ContentPlaceHolder> and are mapped to their respective content placeholder controls by the contentplaceholderid attribute. The content placeholders define default content for the region defined by the content placeholder control. The default content defined by content placeholders can be modified within the master page so that the changes appear on every page to which the master page is attached.
By using master page we can create a single page template and then use it as the basis for the multiple pages, instead of having to build each new page from scratch.
The master page is the base [Main or we can say Root] from which everything else is can built. Every page on your site will use the same master page or may be different master page , so you’ll want to hardcode only those HTML elements on the master page that are common to every page in your site, such as the header and footer. This is also where you reference any .NET components that will appear on every page on your site, such as
1. Navigation controls.
2. Map Control
3. Site Logo and Copyright Text.
Lastly, you’ll add “holes,” called “content placeholders,” to your master page that the page layouts you write will fill in. Think of these content placeholders as the areas where the HTML changes from page to page. You can add any number of these placeholders throughout your master page and they can hold any size HTML. For example, you could have a small placeholder in the header that pulls in a different image from each of your page layouts, and a larger one below your header that allows each page layout to change the entire design and layout of the content area of your page. The code for content placeholders looks like this:
In the master page:
How much HTML you put in the master page and how much you put in your page layouts depends on how much you want each page to differ from the master page. When you want a site that contains drastically different pages with varying numbers of columns and features, you’ll want to put most of your HTML in the page layouts and include large content placeholders on your master page. In contrast, when you want every page to be very similar, you can put most of your HTML in the master page and leave your page layouts fairly slim.
So end users can customize the content on your pages, the page layouts themselves contain “holes” that are editable through the web browser. These holes consist of field controls or web part zones, and will look something like this:
Rich HTML Field:
<PublishingWebControls:RichHtmlField id = “TopTitleContentKK” FieldName = “KKPageTopContent” runat = “Server”/>
Web Part Zone:
<WebPartPages:WebPartZone runat = “Server” AllowPersonalization = “false” ID = “RightZone” FrameType=”None” Titiel = “RightZone” Orientation = “Vertical” />