Aluminium Shell USB 2.0 to TTL UART 5PIN Module Serial Converter CP2102

The so-called USB to TTL converter is actually a USB Serial Port to CMOS Logic-Level Serial Port converter. It has two ends: a USB connector, and four wires made to attach to terminal posts. It contains a chip that’s able to trick your laptop into thinking a serial port is installed. You plug the USB port into your laptop, and it appears to your laptop as a new serial port. It uses standard laptop USB serial port device drivers. You connect the four wires up to power, ground, serial RX and serial TX on an Arduino or other development board, these signals use the correct voltage levels for the development board rather than conventional RS-232 levels, and it appears to your Arduino that something is talking to it over its serial port.