Support to select wifi USB adapters and internal wifi driver

I have installed Zorin 8 Ultimate/Core/Lite os. es to my desktop and laptop computers and all wifi connections are working now. To make this happend it was however a tour of different quides, adapters and drivers. I bought a new adapter to be used with my laptop due to I did not manage to use internal wifi after installation. The internal did not start to work. I went to store and took an adapter to have Linux support. That was the only selection criterium. Did I select the right one or not, I had no Idea. However it started to work only plugged in to USB port. It is a Air:Link 25150 type Mini USB Stick. Later on I saw that it "Complies with 2.4 GHz 802.11n and backwards compatible with IEEE 802.11b/g standards." It is a Ralink 802.11 n WLAN chipset. After that I saw that I have Broadcom BCM 4312 802.11 b/g LP-HPY internal wifi in my laptop that did not work. However it refers to the same standard. For some reason the following step was to try to change the drivers and I find from Ubuntu documentation following:

Type to terminal:

sudo apt-get purge bcmwl-kernel-source
sudo apt-get install linux-firmware-nonfree

and restart the computer.

Even if this worked so I am still wondering why the USB Adapter worked but the internal did not. What is the difference to these drivers and hardwares used. My question here is could someone make a tutorial for wifi Adapters selections installations and drivers to be little more secure with things to be solved to get a good result to installations.

The only difference is that the firmware for the USB adapter was already included in the kernel. This is why it just worked out of the box.
For the internal wireless card you just had to download and install the firmware yourself.