Hi, I don´t speak english so sorry if you can´t understand my question
 I´m relatively new in the world of music production, and still learning about terms for effects, kinds of sounds and that kind of stuffs, but there is one sound or group of sounds that i don´t know how to call them, I mean that part between the melody and the drop.
I´ve heard them called ¨Breakdown¨ or ¨Drum fills¨ sometimes this transitions are made with drums or a sound effect I know that but...

How i can find them in youtube? They had another name? How can i made that transition effect?

Thanks for answering