Final answer:
In IPv6, a subnet address defines a group of computers with addresses that have the same prefix. Subnets allow for better network management and routing efficiency and can have different network policies and configurations applied to them.
Step-by-step explanation:
In IPv6, the subnet address defines a group of computers with addresses that have the same prefix. A subnet is a logical division of an IP network, where a common prefix is used to identify a group of devices. This allows for better network management and routing efficiency.
For example, if you have an IPv6 address block of 2001:0DB8:AC10::/48, you can create multiple subnets by extending the prefix. So, 2001:0DB8:AC10:0000::/64 could be one subnet, and 2001:0DB8:AC10:0100::/64 could be another subnet. The computers within each subnet share the same prefix (2001:0DB8:AC10 in this case).
By organizing computers into subnets, administrators can apply different network policies, security settings, and address configurations to each subnet, making it easier to manage a large network with numerous devices.