[Arduino Uno R3] To turn on LED by each level using analogWrite.

You can turn on LED by each level using analogWrite.
analogWrite function has 2 parameter.
analogWrite function's first parameter is pinNumber and second parameter is value.
The value can has number from 0 to 255.
Following is electric circuit diagram.

From ~10 port to the resist and to LED.
The ports have a prefix '~' are analog output ports.

Next code is to send eletric from ~10 analog output port to LED.
// Pin 10 has an LED connected on most Arduino boards.
// give it a name:
int led = 10;

// the setup routine runs once when you press reset:
void setup() {
  // initialize the digital pin as an output.
  pinMode(led, OUTPUT);
}

// the loop routine runs over and over again forever:
void loop() {
  byte n = 5;
  for(int x = 0; x < 5; ++x)
  {
    analogWrite(10, x*255/n);
    delay(1000);
  }
}