people have told me, "unplug your modem and plug it back in" ?

Ive got an ADSL modem thats connected to the pc via usb cable then the other cable goes straight into the phone socket.

So i just unplug what to reset my ip? im not sure how unplugging anything would change my ip, if that was the case my ip should change everytime i turn the pc off because the modem is obviously powered by the pc

Oh im confuzzled, someone enlighten me please