Arduino can send output through serial communication to your computer over USB. The output can be anything such as status, text, sensor reading, value, number etc. You can view the status output by clicking Serial Monitor button at Arduino Environment software.
Instruction;
1) Connect your arduino to your computer using USB cable A plug to B plug.
Upload this code to your arduino
/*
Serial Communication
Arduino can send output through serial communication to your computer over USB.
Coded by: arduinoprojects101.com
*/
void setup() {
Serial.begin(9600);
}
Read more: Arduino Serial Communication Code