osCommerce Main Categories Introduction
The osCommerce Categories Box, Categories Tree or Main osCommerce Categories allows visitors to navigate through the product categories easily. The default osCommerce shop use Parent Categories - Sub Categories hierarchies structure. Actually most osCommerce shop use Parent Categories or Parent Categories - Sub Categories hierarchies structure. There is rarely that an osCommerce shop use Parent Categories - Sub Categories - Sub Categories hierarchies structure.
Let's see how the osCommerce Main Categories Works:
Visiting osCommerce Homepage:
When browsing the osCommerce homepage, only the osCommerce Parent Categories (Hardware, Software and DVD Movies) will be shown.

Visiting osCommerce Parent Categories
When browsing the osCommerce Parent Categories (Hardware, Software and DVD Movies), the Sub-categories of that Parent Categories will be expended or listed.
Hardware Parent Categories:

Software Parent Categories:

DVD Movies Parent Categories:

Visiting osCommerce Sub-Categories
When browsing the osCommerce Sub Categories (CDROM Drives, Garphics Cards, Keyboards, etc.), the Sub-categories of that Parent Categories will still be expended or listed.
Hardware Sub-Categories:

Software Sub-Categories:

DVD Movies Sub-Categories:

The coming osCommerce tutorials will study the file or code structure of Main Categories. After studying the file structure, this is much easier to customize the Main Categories.
Please read on...