What is a characteristic of public IP addresses?

Public IP addresses are assigned to devices that need to communicate over the internet. This characteristic facilitates global accessibility, enabling devices to send and receive data across different networks without being restricted to a specific locality. Each public IP address is unique across the entire internet, ensuring that data packets reach the intended destination without confusion.

In contrast, other characteristics described in the options pertain to private IP addresses or specific scenarios within local networks. For instance, private IP addresses are used for internal communication, are not routable on the internet, and provide security within local networks. Public IP addresses are not restricted to a local network; rather, they are essential for maintaining a device's presence on the broader internet. Furthermore, while some public IPs may be dynamic—changing over time—there are also static public IP addresses that remain constant, which shows that they are not inherently always dynamic. Thus, the defining trait of public IP addresses is indeed their assignment to devices for internet accessibility.