A Storefront is designed so that multiple pages share a common header and footer layout.

< isdecorate > is specifically designed for reusable page layouts. A page template wraps its page-specific content in < isdecorate template= " ... " > , while the decorator template defines the shared structural markup—typically the HTML shell, header, navigation, footer, and other common elements. The decorator contains < isreplace/ > at the position where the wrapped page-specific content is inserted.

Salesforce describes a typical < isdecorate > use case as decorating the page body with a common header and footer. This makes it the most effective mechanism for reducing repeated layout code across multiple storefront pages.

< isreplace > is not normally selected by the page that consumes the layout; it is placedinside the decorator templateto identify the insertion point. < isinclude > is useful for reusable partial templates but does not provide the same complete page-layout composition semantics.

Using decorators also improves maintainability: a change to the common header or footer is made once in the decorator rather than repeated across every page template.

Study Guide reference:Application Development — ISML template decorators, < isdecorate > , < isreplace > , common layouts, and reusable storefront presentation.

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