What is this component?
I don't how to search for it. It has only "4 4" written on it; I didn't get any search results from it.
Does anyone know what this SMD component is, and what it is used for?
It is a ceramic chip antenna, and it does what antennas usually do.
Its specs (but not its make and model) are in chapter 7 of the module's datasheet which can be found on Adafruit's website.
Maybe with this information you can google make and model, or find a similar one.
https://www.adafruit.com/product/3406?amp& check this video out. It explains every single compenents on it. So, according to video, it is the antenna.