Raspberry Pi HATS (Hardware attached on top) are other boards and modules that extend the functionality of your main Raspberry Pi boards. These expansion boards can help you do more with your Pi, whether its a Pi 2, Pi 3 or the latest Pi 4 boards. The Raspberry Pi boards support both official HATS and third-party hats to make your experience even greater and to open up more availability with what your device can do.
Raspberry Pi add-ons are also included and you can find the likes of additional heatsinks to cool your device to an even more optimum temperature for better performance. Raspberry Pi hats are mostly plug and play for an effortless install.