Is and 802.11 b/g/n WI-Fi module wich became very popular becouse of its capabilities and ease of use and integration .
Many electronics hobbyists are building procjects on ESP8266 and they generally need to connect the module to their PC or microcontroller.
Electro Labs made one ESP8266 Development Board wich lets the user make connection to ESP8266 a PIC microcontrollerand a PC, the board also provides all the needs to be used as microcontroller peripherals such as :
LCD display ,pusbuttons ,indicatorLEDs and GPIO extension.
There are eight pins on the ESP866-01 module; the pinout module is ;
1:GND; 2:TX; 3:GPIO2; 3:CH_PD; 5:GPIO0; 7:RX ;8:VCC.
TX and RX are the UART communication lines of the module, they are both connected to FT232RL and microcontrroler .
FT232RL is a very popular USB to UART converter, it can create both 3.3V
and 5V communication.
Source : www.electro-labs.com