Canning Tongs are used for lifting preserving jars into and out of boiling water.
They are made to fit around the neck of jars, and grasp under the lowest ridge on the neck. That way, it doesn’t disturb the lids that you’ve been working on sealing. Some have their gripping ends rubber-tipped for increased grip.
They have long handles to protect your hand and forearm from being scalded by steam.
They can also be used for large items like lobsters. They are not of any use for small items.
Regular tongs are also useful during canning to get lids, lid inserts, etc out of the boiling water they were sterilized in. These regular tongs will have a finer grip and allow you to pick up these smaller items.
You position the arms of the Canning Tongs around the neck of the jar, close the tongs, and lift.