SharePoint page edit issue

I am using SharePoint Server 2007 Enterprise with Windows Server 2008 Enterprise, and I am using publishing portal template. I am using SharePoint D开发者_JS百科esigner 2007 to design pages. When I open the default.aspx under Pages sub-folder of a site, there are two options -- Edit in Browser and Edit Page Layout. I want to know what are the differences between Edit in Browser and Edit Page Layout -- especially what is the function of Edit Page Layout, because when I select Edit Page Layout, WelcomeSplash.aspx opens in SharePoint Designer, other than default.aspx itself (very confused).

thanks in advance, George

The page layout is default.aspx's backing "template". It holds the actual controls. Edit page layouts to move around controls etc. You can also create your own and bind them to content types.

Edit in browser basically means you edit the values of say the title control, or the content of a richtext fieldcontrol. This is usually done through sharepoint's front end web UI. You can also change a page's assigned pagelayout to a different one, i.e. have default.aspx use ArticlePage.aspx as pagelayout instead of WelcomeSplash.aspx. THis is done in the publishing console in the web ui as well.