Questions

IP address is the (›Internet Protocol) - a unique number that computers (and other devices) use to identify and communicate with one another on a network.

Your computer's IP address can either be static or dynamic.
Static IP address is allocated by your Internet services provider (ISP) and is usually mentioned on your contract - it remains the same each time you log on to the Internet and therefore your computer can be identified by it when connecting to a website.
Dynamic IP is set by a remote server (DHCP) and changes each time you log onto the Internet or restart your router, this is often the case with connecting to the Internet via mobile phones.
Your domestic or office router IP address may or may not change after re-booting, your IP might remain the same for many months and then change.

if you do not know your IP address you can find it by going to: ›cpanel.net/myip