IP address
An Internet Protocol address (IP address) is a numerical label assigned to each device connected to a computer network that uses the Internet Protocol for communication.
An IP address serves two principal functions: host or network interface identification and location addressing.
Martian packet
A Martian packet is an IP packet seen on the public internet that contains a source or destination address that is reserved for special-use by Internet Assigned Numbers Authority (IANA). On the public Internet, such a packet’s source address is either spoofed, and it cannot actually originate as claimed, or the packet cannot be delivered.