What happens if you plug a USB 2.0 into a USB 3.0 port?

Is USB 3.0 backwards compatible? … You can plug a USB 2.0 device into a USB 3.0 port and it will always work, but it will only run at the speed of the USB 2.0 technology. So, if you plug a USB 3.0 flash drive into a USB 2.0 port, it would only run as quickly as the USB 2.0 port can transfer data and vice versa.