Need clarification with arduino syntax I've been learning how to program this fine piece of equipment but i seem stuck. I came upon the "Knight rider" example where you are supposed to blink LED's from one side to another and i can't understand where some of the code comes from. For example:

byte ledPin[] = {4,5,6,7,8,9,10,11,12,13};
int ledDelay;
int direction = 1;
int currentLED  = 0;
unsigned long changeTime;
int pot = 2;
int i;

void setup()
{
    Serial.begin(9600);

    for (i = 0; i &lt; 10; i++)
    {
        pinMode(ledPin[i], OUTPUT);
    }

    changeTime = millis();
}

void loop()
{
    ledDelay = analogRead(pot);

    if ((millis()- changeTime) &gt; ledDelay)
    {
        changeLED();
        changeTime = millis();
    }
}


void changeLED()
{
    for (i = 0; i &lt; 10; i++)
    {
        digitalWrite(ledPin[i], LOW);
        Serial.print("i = ");
        Serial.println(i);
    }

    digitalWrite(ledPin[currentLED], HIGH);

    currentLED += direction;

    if (currentLED == 9)
    {
        direction = -1;
    }

    if (currentLED == 0)
    {
        direction = 1;
    }
}


In this code I don't  know where the "direction" variable is coming from I searched on the arduino reference page but can't find it. Are there other references where I could look or am I misunderstanding something?
It's coming from the program itself:

int direction = 1;


That means "Create a signed integer called 'direction' and assign it the value 1.