meaning of visited link

I could not understand the exact meaning of visited link.
If we assign some color to visited link, of course the link color changes when we click that link.
But how long does the link color remain in the visited status?
I closed the browser and restarted and went to the same page. I even shut down the PC and again visited the same page after restarting the PC! But the link was in the visited status. Is it a permanent condition for a given user and PC?

thank you, sir

Hi

Ya browser will cache your page, so if remove your cache it will come

Regards