AirTag is designed to work with an iOS device that has been updated to at least iOS 14.5, such as an iPhone, iPad, or iPod touch. The AirTag uses the Find My app to share its location with the connected device, which then provides location updates to the user.
Without a connected device, the AirTag will not be able to share its location or provide any tracking capabilities. However, if the AirTag is lost or found by someone else with an iOS device, they can use the Find My app to identify and contact the original owner. The AirTag itself does not have any way to communicate directly with the internet or any other device.