What are the elements of an IPv4 address?
IPv4 addresses are represented by decimal-dot notation, consisting of four decimal numbers, each ranging from 0 to 255, and separated by dots, for example, 192.0.2.10. Each part represents a group of eight bits (an octet) of the address.
The octets are divided into network and host portions based on the subnet mask assigned to the address. For example, the IP address of 192.0.2.10 with a standard Class C subnet mask of 255.255.255.0 indicates that the network portion of the address is 192.0.2, and the host portion is .10. It also indicates that the range of hosts on that network is 192.0.2.1 to 192.0.2.255.
See these pages for more information on IPv4 addresses and subnetting: