GameObject.tag

The tag of this game object.

A tag can be used to identify a game object. Tags must be declared in the tag manager before using them.

JavaScripts

gameObject.tag = "Player";

using UnityEngine;
using System.Collections;

public class example : MonoBehaviour {
void Awake() {
gameObject.tag = "Player";
}
}

import UnityEngine
import System.Collections

class example(MonoBehaviour):

def Awake():
gameObject.tag = 'Player'