PrestaShop has a neat feature to import and export products in the back office. PrestaShop is so powerful that it allows you to import and export many things: categories, products, combinations, customers, addresses, brands, suppliers, aliases, orders, and contacts.
In this article, I will discuss the following:
How To Import Data Into PrestaShop
Suppose you log into the back office and click to manage any content type (categories, products, combinations, etc.). In that case, you can find the Import button by clicking the cog icon in the top-right corner.

On this page, you will see sample files you can use to construct your future import files.

To improve import quality, try to use a CSV file as it is fundamental and will never have any importing issues because of the formatting or styles used in the document.
When you hit the Next button, you will be presented with a data preview to double-check if your data is correct. Hit Import if the information is in good shape.

How To Export Data Into PrestaShop
In the back office, for every content type, you can click the cog icon in the top-right corner and select the Export feature.

This will present a downloadable CSV file that you can open with LibreOffice or Microsoft Word.
CSV file format is highly recognizable. However, most likely, you will have an import feature in any other system like Magento or WooCommerce.
Conclusion
More PrestaShop configuration topics are in PrestaShop customizations blog.