This is a high-quality CP2104 USB-Serial chip that can upload code at a blistering 2Mbit/s for fast development time. It also has auto-reset for Arduino/ATmega328 boards so no noodling with pins and reset button pressings. The CP2104 has better driver support than the CH340 and can do very high speeds, and variable speeds without stability issues. Compared to the FT232RL and FT231X, the CP2104 has the same capabilities or better, at a great price! It even has the RX/TX LEDs to help you debug your data, they'll blink when the chip receives/transmits data.
The 6th pin is RTS, the power wire is +5V and the signal levels are 3.3V (they are 5V compliant, and should work in the vast majority of 3.3V and 5V signal systems). Works excellently with any Arduino, ESP8266, ESP32 or any other microcontroller that uses an 'FTDI port' for communications and upload.
There's also a full collection of all the modem control pins you may need on the side, in case you need the DTR, RI, DSR, etc. pins.
Each order comes with a fully assembled and tested board. A right-angle socket header and a male header strip is included. You can solder in the socket header on the edge to make it 'FTDI-like' or solder the male headers in to plug it into a breadboard and get access to all the pins.
For Linux you won't need a driver. For Windows, it will automatically grab the driver from Windows Update. For Mac OS X you can check out SiLabs driver page for the latest and greatest.