Raspberry Pi pico microcontroller. we can use it by MicroPython & C/C++ programing language.
first you press bootset button and connect pc.
then "rp2-pico-20210902-v1.17.uf2" is the microPython file where we can get on Raspberry official website.just download and drag and drop to pico board.
Here I include "raspberry-pi-pico-python-sdk.pdf" book.It will help you much.😉😉