Help for Aimeos

How to create your own functionality using the aimeos structure. For example, I want to create a reporting system or a simple chat or an email template builder, while I don't want to create new tables, but I want to use aimeos tables to store data related to my functionality. How can I organize the ...

Aimeos has the ability to create extensions, add plugins and services. What's the difference between them in aimeos?

Thank you!

Why is this filter not working? $productFilter->add($productFilter->and([ $productFilter->is($productFilter->make('product:prop', ['vendor_code', null, $productData[0]] ), '!=', null), $productFilter->is($productFilter->make('product:prop', ['barcode', null, $productData[8]] ), '!=', null), ]))->add...

I have three kinds of sizes us, eu, ru.
Do I need to create three different attributes or can I create an attribute then sub-attributes(ru, en, us)?