MonoBehaviour.Update()

설명

Update is called every frame, if the MonoBehaviour is enabled.

Update is the most commonly used function to implement any kind of game behaviour.

using UnityEngine;
using System.Collections;

public class ExampleClass : MonoBehaviour {
    void Update() {
        transform.Translate(0, 0, Time.deltaTime * 1);
    }
}

In order to get the elapsed time since last call to Update, use Time.deltaTime. This function is only called if the Behaviour is enabled. Override this function in order to provide your component's functionality.