Separating Page Design and Component Design
Page visualization is handled by a Page Template and content visualization is handled by a Component Template.
About this task
You might logically expect to have to create an Adobe Dreamweaver Template to use in a Page Template and a different Adobe Dreamweaver Template to use in a Component Template.
However, Adobe Dreamweaver has no conception of Components; a Component is a concept proprietary to SDL Tridion Sites. As a result, an Adobe Dreamweaver Template (a .dwt file) can, as a whole, only be used to transform Pages, not Components.
The solution to this problem is to create a .dwt file that contains an identifiable section devoted to the transformation of a Component, and then specify in your Component Template which identifiable section that is. The Component Template then ignores the rest of the .dwt file, but uses the identified section to transform the Component.
You could make a specific .dwt file for use in a Component Template. If you do that, anything outside the identifiable section is always ignored, and is therefore irrelevant. In addition to that, you could have a separate .dwt file for use in a Page Template.
But it is unnecessary to have separate .dwt files for these purposes. Instead, it is better create one Adobe Dreamweaver Template (.dwt file) that you can use both for a type of Page and for one or more types of Components. You add this multi-purpose file as the binary content of a Template Building Block that you can use in a Component Template to visualize a Component, and in a Page Template to visualize a Page.
Note that this multi-purpose Template Building Block specifies only one possible visualization of a type of Component. You can create any number of Dreamweaver Template Building Blocks, specifying different visualizations of the same type of content. For example, you can create one Dreamweaver Template Building Block that shows all the content fields of the Component, and another that shows only a few fields, to provide a 'summary' visualization.
Procedure
Results
You now have a single Adobe Dreamweaver template that you can use to visualize Component and Pages.