The term "address unavailable" generally means that a location service or app has located the device or person but cannot find or associate a precise street address with that location. This often occurs because the exact street address is not available in the map database for the given location or the location data is not accurate enough to determine a specific address. It could also happen due to weak GPS signals or poor network connection that prevent precise location details from being obtained. For example, in Apple's Find My Friends or Find My iPhone apps, "address unavailable" means the device's location is known at some general level but the system cannot provide a specific address like "185 Main Street." Causes include GPS issues, device being offline, location services turned off, or lack of street address data in the area.

In contrast, "location not available" or "location not found" often means the device cannot be located at all, typically when it is off, has no signal, or location sharing is disabled.

Hence, "address unavailable" signals limited location precision rather than complete loss of location data.