Question on short/long positions

Hi there!

So i saw binance's videos on taking short/long positions, but there is something i don't understand: how long can i hold a position and when will Binance sell my position if it's going the other way. So what I understood is that the position can be hold as long as we want, and we pay 3.5% every year, is that right? And the position is automatically sold when the price reached a % that is esuivalent to what i borrowed right? Is that what people call "liquidation"? For example I have 1 btc and borrow 2 btc to take a long position, then my position is automatically sold if the price of btc drops by 34%?