WHAT IS IP ADDRESS
An identifier for a computer or device on a TCP/IP network. Networks using the TCP/IP protocol route messages based on the IP address of the destination. The format of an IP address is a 32-bit numeric address written as four numbers separated by periods. Each number can be zero to 255. For example, 1.160.10.240 could be an IP address.

WHAT IS IP/INTERNET PROTOCOL

Internet protocol is the set of techniques used by many hosts for transmitting data over the Internet. The current version of the Internet protocol is IPv4, which provides a 32-bit address system.
Internet protocol is a "best effort" system, meaning that no packet of information sent over it is assured to reach its destination in the same condition it was sent. Often other protocols are used in tandem with the Internet protocol for data that for one reason or another must have extremely high fidelity.

IPv6
IPv6 stands for Internet Protocol version 6. It is the second version of the Internet Protocol to be used generally across the virtual world. The first version was IPv4. IPv5 was a protocol of a different sort, intended to support video and audio rather than all-purpose addressing. IPv6 is also known as IPng, which stands for IP Next Generation.

IPv4
Internet Protocol version 4 is the fourth iteration of the Internet Protocol (IP) and it is the first version of the protocol to be widely deployed. IPv4 is the dominant network layer protocol on the Internet and apart from IPv6 it is the only standard internetwork-layer protocol used on the Internet.
It is described in IETF RFC 791 (September 1981) which made obsolete RFC 760 (January 1980). The United States Department of Defense also standardized it as MIL-STD-1777.

WHAT IS THE IP ADDRESS OF THE ROUTER
A typical home network router possesses two IP addresses, one for the internal home (LAN) and one for the external Internet (WAN) connection. How can you find the router IP addresses?
Answer:

How do I hide my IP address?

What is the IP address of my computer?

PC users with Windows 98/ME

Start an MS-DOS prompt (from the Start Menu/Programs) and type the command
ipconfig

PC users with Windows 2000/XP

Start a Command prompt (from the Start Menu/All Programs/Accessories) and type the command
ipconfig

CHANGING YOUR INTERNET IP ADDRESS
Modem users
When connecting to the Internet, your ISP will assign your computer an address each time you connect. This means that often each time you connect you'll have a different IP address. If you're wanting to change your IP address, try disconnecting and reconnecting.
Broadband users