ESP8266 Module. Both Type 1 and type 2 is similar pinout exept for the Reset pin which is not included on the pinout on Type 2. Both modules uses The ESP8266 chipset though the USB to serial converter on type 1 is The CH340 and CP2102 on Type 2. Though we normally stock both, Type 2 has became hard to find due to the silicone crisis.
Coding on Arduino is identical on both. Select NodeMCU V3 for your development.