Provides power to your project. Most YP-05 modules have a jumper to toggle this between 3.3V and 5V .
There are many USB-to-Serial modules (like the CP2102 or CH340G), but the YP-05 (FT232RL) remains a favorite for several reasons: yp-05 pinout
Are you planning to use the YP-05 for or for debugging a different type of hardware? Provides power to your project