USB Driver: CH340GA convenient solution for developing new projects that require Wi-Fi. Through USB, you can update sketches and firmware for both ATmega328 and ESP8266. For this on board, there is a UART converter CH340G.The board has a DIP switch, which switches the modes of interaction of microcontrollers ATmegaa328 and esp8266. The operations of this board are very simple. The board has a DIP switch, to connect the modules. For example, to USB and ATmega328, USB and ESP8266, ATmega328 and ESP8266. Wi-Fi’s radio bands have relatively high absorption and work best for line-of-sight use. The signal strength of Wi-Fi is affect by multiple factors, but it generally decreases with distance.ATmega328P USB-TTL
Supply Voltage: 6~9V
Type: Logic ICs
MCU: ATmega328
WIFI MCU: ESP8266

Arduino UNO WIFI ATmega328P Features:

UNO WIFI ATmega328P ESP8266 Chip CH340G , is a budget solution. When you work in the frequency 12Mhz, giving a stable result of data exchange (need install drivers to computer).

• Uno R3 CH340G/ATmega328 – connects to the computer via micro USB cable (used for almost all Android smartphones).
• You can supply power to the board through a Micro USB connector or DC power socket.
• The voltage regulator (LDO) can deal with incoming voltage from 6V to 12V DC.
• The convenient solution for the development of new projects requiring Uno and WiFi
• Wi-Fi uses multiple parts of the IEEE 802 protocol family and is designed to work seamlessly with its wire sibling, Ethernet.
• Compatible devices can connect through a wireless access point (WAP) with each other as well as with wired devices and the Internet.
• Different versions of Wi-Fi are specified by various IEEE 802.11 protocol standards, with different radio technologies determining radio bands, maximum ranges, and speeds that may be achieved.
• Wi-Fi most commonly uses the 2.4 gigahertz (GHz) or 120 millimeters (mm) ultra-high frequency (UHF)
• en.wikipedia.org