Devices provides you with an overview of the currently and previously connected devices. It also allows you to customize the firewall options per device.
If a device is connected through DHCP, its name will default to the host name. You can change its name by clicking 1. To revert the name to its host name, you can clear your custom name.
If you select a device, you can monitor its download and upload usage in 2, and specify any speed limits. In 3, you can change whether it has access to the internet and your local network.
Furthermore, you can hover over 4 to get additional information about the device, such as its host name, IP address, and MAC address.
You can permanently delete a previously connected device by clicking 1. This will also remove its custom name, speed limits, and firewall options.