What is Fatigue system

Can any one please tell me what is fatigue system and how it works

According to the silkroad time, you have a maximum stay of 8 hours a day. At the end of these 8 hours, if there is no VIP or exp sp premium ticket, you will be disconnected from the game. you have to wait for silkroad online time to be 00:00 to know it will re-enter.

I know this way, if anyone knows differently, they can inform me.