Class division in IP addressing was established to efficiently allocate and manage the limited number of available IP addresses. The division into classes (A, B, C, D, and E) allows for different network sizes and types, making it easier for organizations to choose an address scheme that fits their needs. Class A supports large networks, while Class C is more suited for smaller networks. This hierarchical structure simplifies routing and network management, although it has become less relevant with the advent of CIDR (Classless Inter-Domain Routing).
Class B, if you are referring to classful addressing schemes.
The difference between classful IP addressing and classless IP addressing is in selecting the number of bits used for the network ID portion of an IP address. In classful IP addressing, the network ID portion can take only the predefined number of bits 8, 16, or 24. In classless addressing, any number of bits can be assigned to the network ID.
Class C
In classful addressing, the class of an IP address can be determined by the value in the first octet: 0 - 126 class A 128 - 191 class B 192 - 223 class C
For multicast, ip addresses in the range of 224.0.0.0 - 239.255.255.255 are used.
An IP address is divided into the network and host (computer) portion. Where the division is made depends on the address class A/B/C or the now more usual classes addressing the netmask.
Static IP
Class D
No, not all Class B addresses are APIPA addresses. APIPA (Automatic Private IP Addressing) specifically refers to the range of IP addresses from 169.254.0.1 to 169.254.255.254, which is used for automatic private addressing when a device cannot obtain an IP address from a DHCP server. Class B addresses encompass a broader range from 128.0.0.0 to 191.255.255.255, which includes both public and private addresses, but only a small subset of APIPA addresses.
There are a couple of places where someone can learn about IP addressing. Check out Microsoft's official website for more information and the website called What's My IP.
MAC addressing. IP addressing. port addressing. specific address.
In classfull addressing schemes each address class limited the total number of clients per network. Other than that, there are no particular functions for each address class.