It generates the clock, acts like a serial port, acts like a disk drive, and so on. However, the ATMega32 doesn’t directly have Arduino IDE support so you have to install a toolchain for it.

If you use the Arduino IDE to program the ESP32, you might be interested in [Andreas Spiess’] latest video (see below). In it, he shows an example of using all three ESP32 UARTs from an Ardui… ...