Product feature

I am not sure if Opencart have this ......I am coming from CS-Cart and there is this FEATURES for products.
So for example, product is in MEDICINE category. But I need to mark product for which purpose is this medicine. So I must have "FEATURES" like for headache, for ears, for eyes, for stomach or whatever. And this should be displayed in product tab which i create. On CS-Cart this is set through FEATURES and it can be displayed to a tab.
I am not sure how to set this on OpenCart , through what option or if i need extension, which extension do I need.

It's called Attributes in opencart. Check the opencart demo. It's the specification tab at http://demo.opencart.com/index.php?rout ... duct_id=43

I don't know if this is it. I will explain some more. In CS-Cart this is called Features (Add and manage extra product fields). So I can set for example:
GROUP and under this variants is list which belongs to GROUP, like Alcohol, Eter, Fenol, Flower.etc.
Then there is for example PURPOSE and under this list is , Alergies, Bacterial infections, etc.
So for each product you can select this Features and you can make multiple selections and then you can have this displayed under tab called Features. Here is how this can look like.
http://postimg.org/image/wmab55u1p/
I am not sure how can I set this in OpenCart under attributes ? I searched extension for Opencart for Extra product fields, but this extension are creating Extra product fields like for description or such, not the way I described here.

ok, then categories is the only thing that is kind of like that.