What is the main characteristic of a static IP address?

A static IP address is defined primarily by its constancy; it does not change over time. This feature allows devices that rely on a constant IP address for their operation—such as servers, network printers, and security cameras—to maintain consistent communication with other devices on the network.

Having a static IP simplifies tasks like remote access and DNS setup, as the address assigned to a device remains the same, eliminating the need for constant updates or adjustments in configurations when changes occur. This characteristic is particularly beneficial for businesses and services that need to ensure reliable interconnectivity and access.

The other options don't accurately describe static IP addresses. For instance, automatic updates pertain to dynamic IP addresses, which regularly change at intervals. The notion that static IPs are used exclusively for internal networks is incorrect as they can also be utilized in external networks. Finally, the idea that static IPs are not routable confuses their operational context, as static IPs can be routable just as dynamic ones are, depending on their configuration and use.