Answer :

hidden viruses take their time and wait until they make the host cell produce more of the virus..
kind of like a ninja, waiting to spring at any moment.

The genes of a hidden virus remain in your cells forever. You can never get rid of them and they can become active at any time.
The difference is that a hidden virus is everywhere inside your cells and cant be taken out[ But can activate anytime]. Active viruses can be treated after you go to the doctors office and look at the symptoms. so basically active viruses can be treated dormant viruses cant until activated.