What drop filter means

what is that? i saw many ppl talking about it, but i dont have ideia of what it is, can someone explain me? (im new)

 

It's part of the premium service. Basically, you can filter out items you do not want to pickup while grinding, based on color and enchantment level. There is also a list if items that are completely ignored by the filter. Instructions for the filter are listed both on discord in general english pins, and in the Questions and Answers thread in faq support. There is also some information on it here: http://forum.gameznetwork.com/threads/common-questions-and-answers.220983/