AirTags is one of those upcoming Apple products, the release of which there has not been much doubt for a long time, but we did not have any special details.
Recall that Apple AirTags, judging by the rumors and leaks, are small devices like Bluetooth tags that will be used for roughly the same purpose. That is, they can be attached to various objects, so that then these objects were easy to find. It can be keys, a wallet, a passport and anything, you can forget something at home, or it is often difficult to find.
AirTags will be integrated with the Find My app on the iPhone. Through the application, you can easily find the right thing or configure the software so that it notifies the user that he has moved away from a particular thing quite far. For example, leaving home, I forgot my wallet.

For operation, AirTags will presumably use the Ultra Wideband (UWB) format. Recall that in the current line of iPhone there is a U1 transceiver, which is currently not used. It will be he who will be responsible for detecting AirTags.
So, if there were a lot of rumors and leaks about AirTags, now we can talk about them with confidence. Apple itself, which is extremely rare, accidentally talked about them in its latest instructional video. Now it has already been deleted, but the screenshots remain.

As you can see, they have a mention of the AirTags themselves, and their purpose is to detect objects lacking the usual means of communication in the form of Wi-Fi or a cellular modem.
It is believed that AirTags tags will be presented in the near future along with a number of other Apple innovations, including the long-awaited iPhone 9.