What is wrong with my tab?

[709]

Is it my internet connection or something? Just days ago, my Samsung tab was working just fine. I was connected to an internet connection and all of a sudden, one day, my tab says it's not connected. Everything at my house is on. WiFi is on, the net, cable, everything. I am able to connect anything but my tab. I've tried everything but it keeps saying it's connecting and then it'll say "authentication error occurred." Does anybody know why this is happening? I've tried restarting the modem and still. Nothing has changed.