What is the key difference between IPv4 and IPv6?

The key difference between IPv4 and IPv6 lies in their addressing capabilities, specifically the number of addresses each protocol can support. IPv4, which uses a 32-bit addressing space, can accommodate approximately 4.3 billion unique addresses (2^32). This was initially sufficient for the growing number of devices connected to the Internet, but as the number of devices increased, it became clear that this was inadequate.

In contrast, IPv6 utilizes a 128-bit addressing scheme, allowing it to support an astronomically larger number of unique IP addresses (approximately 340 undecillion, or 2^128). This expanded address space is essential for accommodating the vast number of devices and services in today’s digital ecosystem, especially with the rapid growth of the Internet of Things (IoT) and mobile devices.

Thus, the ability of IPv6 to provide a significantly larger number of addresses is a crucial improvement over IPv4, addressing the limitations that were prominent in the earlier protocol.