3. Internet Protocol

The second part of the TCP/IP protocol is IP, or "Internet Protocol". TCP governs how messages are put together and how they are opened.

Internet Protocol allows computers to address their messages to the correct destination, and allows the destination computer to determine whether a message that they receive is meant for them.

Just like TCP, IP can be broken down into two sets of rules: one governing how messages are sent, and one governing how messages are received.

For sending data the IP rules (protocol) tell the sending computer to:

• Add the destination address to each data "packet", so the network knows where the data is going
• Add the source address to each data "packet", so the network knows where the data is coming from.

For receiving data packets the IP rules (protocol) tell the receiving computer to:

• Accept data packets that have the computer's address attached
• Ignore all data packets that do not not contain its own address, as they are meant for someone else.