From Joomla! Documentation
- Meta Keywords. Optional entry for keywords. Must be entered separated by commas (for example, "cats, dogs, pets") and may be entered in upper or lower case. (For example, "CATS" will match "cats" or "Cats"). Keywords can be used in several ways:
- To help Search Engines and other systems classify the content of the Article.
- In combination with Banner tags, to display specific Banners based on the Article content. For example, say you have one Banner with an ad for dog products and another Banner for cat products. You can have your dog Banner display when a User is viewing a dog-related Article and your cat Banner display for a cat-related Article. To do this, you would:
- Add the keywords 'dog' and 'cat' to the appropriate Articles.
- Add the Tags 'dog' and 'cat' to the appropriate Banners in the Banner Manager New/Edit screen.
- Set the Banner module Form Field 'Search By Tags' to 'Yes in the Banner Module Edit screen.
- For articles only, in combination with the Related Articles module, to display Articles that share at least one keyword in common. For example, if the current Article displayed has the keywords "cats, dogs, monkeys", any other Articles with at least one of these keywords will show in the Related Articles module.