title: ESP8266 - How does it understand what "AT+RST" means without the firmware
body: <p>I am new to ESP8266 and to the electronics world. I request you to please be patient if I am mis-understanding a point.</p>
  
  <p>I am using ESP8266-01.
  I successfully re-flashed the at official ai-thinker firmware version 1.1.1 to my module and I noticed that it was being written at memory location 0x00000.
  Later I successfully uploaded a basic blink program using Arduino ide. Again the program was written to the memory location 0x00000(over-writing the firmware I guess).</p>
  
  <p>I want to use it as a web server. The code for that uses the AT commands, something like "Serial.println("AT+RST");"</p>
  
  <p>Now from what I understand the firmware would be over-written. Then how would the module understand what "AT+RST" means?</p>
  
  <p>Thanks</p>