Hi, could you explain the logic of the variants when we use textbox or checbox, please?

Thanks,

Hi, thanks.
I have already tried to understand it in the manual and there is no details, even the manual is excellent.

My question is when we use checkbox or texbox to the variants.

In the case of the checkbox: you can choose all the options.... and it not add the options.... I do not understand the logic

Example: http://www.e-commerce.com.pt/LojaDemo...

In the case of the textbox: how can we use it?

Example: http://www.e-commerce.com.pt/LojaDemo...

Here is the example with radiobuttons that I consider working perfect!

http://www.e-commerce.com.pt/LojaDemo...

Thanks in advance,

Here you have.