IPv4, short for Internet Protocol version 4, is one of the two main versions of the Internet Protocol (IP) used to identify and locate devices on computer networks, including the global Internet. Here are some key characteristics of IPv4:

32-Bit Addressing: IPv4 addresses are 32 bits in length, which allows for approximately 4.3 billion unique IP addresses. Each address is typically represented as four sets of decimal numbers separated by periods (e.g., 192.168.1.1). Dotted Decimal Notation: IPv4 addresses are often written in dotted decimal notation for human readability, where each of the four sets of numbers can range from 0 to 255. Limited Address Space: One of the significant limitations of IPv4 is its finite address space. With the rapid growth of the internet and the proliferation of internet-connected devices, the available pool of IPv4 addresses became exhausted. This scarcity led to the development and adoption of IPv6. Subnetting: IPv4 allows for subnetting, which means dividing an IP address space into smaller, more manageable subnetworks. Subnetting is a fundamental concept in IP network design and management. Private and Public Addresses: IPv4 includes reserved address ranges for private networks, which are not routable on the public internet. These private IP addresses are used within organizations and are translated to public IP addresses by network address translation (NAT) devices when accessing the internet. Classful and Classless Addressing: IPv4 originally used classful addressing, which defined IP address classes (Class A, Class B, Class C, etc.). However, classless addressing (CIDR - Classless Inter-Domain Routing) is now the standard, allowing for more flexible allocation of IP addresses and more efficient use of address space. Transition to IPv6: Due to the exhaustion of available IPv4 addresses, the transition to IPv6 has been ongoing. IPv6 offers a much larger address space (128 bits) and is designed to accommodate the ever-increasing number of internet-connected devices.
While IPv6 is the future of IP addressing, IPv4 is still widely used, and many networks and devices continue to rely on it. Transition mechanisms and technologies have been developed to facilitate the coexistence of IPv4 and IPv6 during this transition period, ensuring backward compatibility and the continued functioning of the internet.

IPv6, short for Internet Protocol version 6, is one of the two main versions of the Internet Protocol (IP) used for identifying and locating devices on computer networks, including the global Internet. It was developed as a successor to IPv4 (Internet Protocol version 4) to address the limitations of IPv4, primarily the exhaustion of available IPv4 addresses. Here are some key characteristics of IPv6:
128-Bit Addressing: IPv6 addresses are 128 bits in length, which allows for an immensely larger address space compared to IPv4. The expanded address space provides approximately 340 undecillion (3.4 x 10^38) unique IP addresses. Each IPv6 address is typically represented in hexadecimal format and separated by colons (e.g., 2001:0db8:85a3:0000:0000:8a2e:0370:7334). Hexadecimal Notation: IPv6 addresses are typically expressed in hexadecimal notation, making them longer but more human-readable compared to the dotted decimal notation used in IPv4. Zero Compression: IPv6 allows for the compression of consecutive groups of zeros within an address. For example, "::" can be used to represent multiple consecutive groups of zeros in an address, simplifying the notation. Simplified Header: IPv6 has a simplified header structure compared to IPv4, which improves routing efficiency and reduces processing overhead on networking equipment. Improved Security: IPv6 includes built-in security features, such as IPsec (Internet Protocol Security), which provides authentication and encryption at the network layer. In IPv4, IPsec is typically implemented as an optional extension. Stateless Address Configuration: IPv6 introduces stateless address autoconfiguration, allowing devices to generate their own IPv6 addresses based on network prefixes and other parameters without relying on DHCP (Dynamic Host Configuration Protocol). Mobility Support: IPv6 includes features that enhance mobility support for devices that move between different networks, making it more suitable for mobile and IoT (Internet of Things) devices. Transition Mechanisms: Various transition mechanisms have been developed to facilitate the coexistence of IPv6 and IPv4 during the transition period. These mechanisms ensure that devices and networks can communicate regardless of their IP version.
IPv6 is considered the future of IP addressing, as it provides a virtually unlimited number of unique addresses, which is essential to accommodate the growing number of internet-connected devices. While IPv6 adoption has been ongoing, IPv4 is still widely used, and many networks operate with dual-stack configurations, supporting both IPv4 and IPv6 to ensure compatibility and a smooth transition to the new protocol.