1. Zone - This is the area on a your website where the ads are placed. You can define any number of zones. You can have many ads in a zone which will randomize. Zones can be defined in Manage Content > Ads > Edit Zones
2. Ad - An ad can be some HTML code, image or flash snippet. It needs to be created from Manage Content > Ads > Create New Ad. An ad may belong to one zone.
Normally, you can use any of the module sections to insert your ads.
For creating a custom zone in your template:
1. You can place it inside any template file (.ctp) using this code:
<php App::import('Helper','Ads.Ads'); $adsHelper = new AdsHelper; echo $adsHelper->show('your_zone_name'); ?>
This requires some technical know-how of PHP though.
2. Save 'your_zone_name' from Manage Content > Ads > Edit Zones.
Note: You can also display ads of a specified zone on any page using module visibility parameters.
After the module is published, you should be able to see the ads