Unicast IP Addresses

• A unicast IP address is used when you want to transmit information across a network to a specific network device.
  
  

Broadcast IP Addresses

• Broadcast IP addresses are classified into four different subnets, known as A, B, C and D subnets. A broadcast IP address allows information to be disseminated, or "broadcast," to all of the computers on a particular subnet rather than one specific computer.
  
  

Multicast IP Addresses

• Whereas a broadcast IP address is used for sending information to all computers on a particular subnet, a multicast IP address is used for sending information to only certain groups of computers on a large domain. Subnet D, in particular, is often reserved for multicasting.
  
  

Private IP Addresses

• Private IP addresses are private because they cannot be routed over the Internet. They are free and available for anyone to use. Since these types if IP addresses are private, different organizations in different locations can use the same private IP addresses without fear of information transmission going to the wrong location.
  
  

Public IP Addresses

• Public IP addresses are the ones most familiar to the layman. In essence, each public IP address is assigned by the Internet Assigned Network Authority (IANA) and cannot be copied. As such, these addresses must be purchased.