What is a USB 'header' (and how is it different from a port)?

With the prevalence of USB devices, it might be easy to mix up USB headers and ports, but there is a key difference between ...
Ars Technica

Hands on with the iPhone Micro USB plug and third-party chargers

The Micro USB plug is very small: just as wide, half as tall, and twice as thick as an SD card. It allows an iPhone be connected to a Micro USB cable instead of the traditional 30-pin connector. The ...
PC World

Next-gen USB connector will (finally!) fit both ways

The next version of the USB connector will accept the plug either way up, the USB 3.0 Promoter Group said Tuesday. The USB Type-C connector, initially intended for USB 3.1 and 2.0 devices, will be a ...