Duplicate content is something that search engine robots don't like.
To avoid it, it's recommended to add canonical links in the header of your shop.
It's also good to:
direct robots to other language versions of your shop with hreflang links
help them navigate through paginated content with prev and next links
prevent them from indexing unnecessary parts of the shop with noindex tag
To achieve all this, we combined some of the common solutions into one handy free module.
You can download the module directly here:
or from this location
(module is for prestashop version 1.6, newer version has canonical tags already partially implemented, so maybe other are coming soon)