To get a verbose list of all devices connected to adb, write the following command in your terminal:
adb devices -l
List of devices attached
ZX1G425DC6 device usb:336592896X product:shamu model:Nexus_6 device:shamu
013e4e127e59a868 device usb:337641472X product:bullhead model:Nexus_5X device:bullhead
ZX1D229KCN device usb:335592811X product:titan_retde model:XT1068 device:titan_umtsds
A50PL device usb:331592812X
emulator-, this device is an emulator.usb: the path of the device in the USB subsystem.product: the product code of the device. This is very manufacturer-specific, and as you can see in the case of the Archos device A50PL above, it can be blank.model: the device model. Like product, can be empty.device: the device code. This is also very manufacturer-specific, and can be empty.