What Is The Difference Between Hide and Close Button？

All system interface has two buttons:  Hide and Close button 

The difference: Close button will close the interface and Hide button only hide it

Hide Button Click button【X】will only hide current window.  When the window is called out next time, it will response very quickly.

Close Button Click button【Trach Can】 will close the window.  When it's called out next time, it will take some time to reload the interface.