The TrafficHAT is an Add-on board for the Raspberry Pi designed to help teach Basic Programming & Soldering. The Add-On meets the requirements of a HAT Add-On for the Raspberry Pi and is compatible with all models that have the 40 Way Pin header format. (A+, B+ & Pi 2s)
GPIO Zero is the new method of interfacing with LEDS, Buttons and more on the Raspberry Pi. It requires a lot less work to get going and is ideal for beginners. Another great advantage is tutorials using GPIOZero are all in Python 3!
However GPIO Zero is still in beta and requires installation. For this see the guide on the GPIO Zero Website.