How to send data from arduino to the ESP8266

Hello, is it possible to send the data from arduino to the ESP8266? For example, i want to send the serial number of an NFC card that is being read in the arduino to my ESP8266. Then from ESP8266, i will send it to a specific IP address. Thank you!

Yes

Yes it's possible.

But you have to tell us how you are using the ESP8266 and how it communicates with the Arduino.

For example are you programming the ESP8266 directly or are you using it in AT mode connected to a serial port on your Arduino?

It may be possible to read the NFC card directly with a program on the ESP8266 without needing an Arduino board.

...R