This document discusses IP addressing concepts including: - IP addresses are 32-bit numbers written in 4 decimal parts - Subnet masks identify the network and host parts of an IP address - Physical network segments are defined as devices connected to the same router port - IP address classes (A, B, C) define the number of bits used for network/host addressing The document provides details on private IP address spaces, subnet masks, IP address notation, and calculating the number of available network IDs and host IDs given an address class.