The Espresso Lite v2 is an ESP8266 development board with a 32-bit RISC CPU running at 80MHz, 64KB instruction RAM, 96KB data RAM, and up to 16MB of external QSPI flash memory. It has IEEE 802.11 b/g/n WiFi, 16 GPIO pins, and UART communication. The document appears to be product documentation for the Espresso Lite v2 ESP8266 development board.