An Internet Protocol Address (commonly known as an "IP Address") is a numerical identifier that's assigned to each device on your local network. Version 4 (IPv4) is used with the ESP8266, which means that address are 32 bits long and often displayed in a human-readable format with 4 numbers, each between 0-255. For example, 192.168.1.1 might be the IP address of your home router.

Most home networks use the Dynamic Host Configuration Protocol (DHCP) to automatically assign an IP address to devices that connect to your network. Because of this, you can't assume that your ESP8266 will have the same IP address every time it connects (unless you manually tell your router to assign it a static IP address).

Sometimes, it can by handy to print out the IP address of your ESP8266 to the console, so that you can reach it from other devices on your network (or even from the Internet).

Using the modify the code from the previous lecture to print the ESP8266's IP Address to the Serial Terminal just after it connects to your network. For bonus points (if such a thing exists on Udemy), have the IP Address appear on an LCD.

For example, printing out the IP address of my ESP8266 hardware connected to my network reveals the following:

Note that printing the IP address in the simulator requires call a specific AT command over UART. Available AT commands for the ESP8266 can be found in this reference guide. If you are using real ESP8266 hardware that can be programmed directly from Arduino, it's good to know that the ESP8266WiFi library uses the same functions found in the Arduino WiFi library.