TA/USB battery charging
I am not sure the question belongs to the forum as its more towards the consumer electronics side. Anyways TA means Terminal-Adapter. And yes there is a big difference between charging through a wall adapter and through the USB.

In order to charge fast, we need to provide the charge at a faster rate, aka more current to be provided at the source. 

A USB does not have a large current output and thus charges the phone slowly, whereas a wall adapter can provide large amounts of current which charges the batteries faster.