Your IP address is a unique number assigned to your router or modem by your Internet service provider. It can be seen by every website and every server (including mail, instant messaging, VoIP and FTP servers) to which your computer connects. As such, an IP address identifies your household, and may identify you personally if combined with other traces like the browser software you are using or your billing information. Currently, most IP addresses look something like this: 188.8.131.52.
However, a new standard called IPv6 is being introduced that will result in IP addresses that look more like this: 2001:0db8:0000:0000:0000:ff00:0042:8329. With this new standard, a unique IP address will be assigned to every computer (or other Internet-connected device). This change will introduce even more privacy risks.