WIFI module ESP-07, ESP8266, 8Mb

The ESP8266 chip module is a highly integrated chip designed to meet the needs of the new connected world. It offers a complete and comprehensive Wi-Fi networking solution, allowing you to either host an application or take advantage of all the networking features from another wireless implementation.
The ESP8266 chip used has an integrated microcontroller that you may/may not use. If you use it, you don't need to connect the arduino at all. This board has 9 GPIO ports and a UART (RXD TXD).

If you connect a digital thermometer/humidistat to this module, set up WIFI as a DHCP client and view the temperature on your mobile, computer or anywhere on the internet!

Specifications:
Extremely small PCB size
There is a connector for external antenna on the PCB
Integrated RF switch, balun, 24dBm PA, DCXO, and PMU
Integrated RISC processor, on-chip memory and external memory interface
Module includes a program for serial link communication using simple AT commands
QOS management
Integrated WEP, TKIP, AES, and WAPI encryption and security
Supports APSD for VoIP applications

Network:
802.11 b/g/n
Wi-Fi Direct (P2P), soft-AP
Integrated TCP/IP stack
Integrated TR switch, balun, LNA
Integrated PLLs, controllers, DCXOs, and power management units
19.5dBm output power in 802.11b mode
Integrated 32-bit CPU can be used as application processor
SDIO 1.1/2.0, SPI, UART
STBC, 1×1 MIMO, 2×1 MIMO
A-MPDU