What are the product types in Magento ?

Magento Simple products :

The most used product type for the Magento store is Simple products. It is the most common product type of them all. A Magento simple product should be used to show a single item without any specific selectable differences.

Magento grouped products :

A Magento grouped products should be used for a combination of Magento's simple products. Think about a coffee cup that is sold together with a saucer, a silver spoon, a breakfast plate or whatever. You can’t define a specific price for a Magento grouped product but you can define a discount amount. 

Magento configurable products :

These products should be used for a single item with a specific selectable variation. Check once about a teacup available in different colours and sizes, a woman’s handbag available in different materials, a light boll available in different watts, etc. Each selectable difference can have its own additional costs based on the available features. 

Magento virtual products :

These products are used for a virtual (not touchable) item. Consider insurance, a booking or a reservation, an extra product guarantee, etc. A virtual product does not allow you to select a shipping method at checkout simply because there is nothing to be shipped. 

Magento bundle products :

It is used for a bundle of simple (or virtual) products that are not to be sold separately. Check for a laptop where the customers can choose various items such as RAM, hard disk, processor, internal memory, or whatever. Each of these items are simple (or virtual) products but these can only be sold within the bundle products. 

Magento downloadable products :

It is used for online software items. Consider an mp3 file, a PowerPoint presentation, a Magento extension, or whatever theme. A downloadable product does not allow you to select a shipping method at the checkout step simply because there is no option and no need to ship.