While some do have it built in like those based on the 32u4 for example, most either don’t have it at all or rely on a separate on-board chip to do some form of translating. The ESP32 is lacking ...

WiFi or other wireless communication chip. On modules like for the ESP8266 and ESP32 platforms the PCB antennas are often integrated onto the module’s PCB, yet even with such a ready-made module ...