Charging with USB 3.0 & 2.0 ports?

I was wondering if I could charge my iPhone with it's USB 2.0 cable in the USB 3.0 port of my laptop. Is 3.0 backwards compatible? Does this apply to other USB 2.0 devices too?

Yes you can.

Usb 3.0 is backwards compatible with 2.0 and 1.1 however usb 3.0 is only increased the data transfer rate and does not decrease the charging time.