GameObject.tag

Description

The tag of this GameObject.

A tag can be used to identify a GameObject. Tags must be declared in the Tags and Layers manager before using them.

Note: You should not set a tag from the Awake() or OnValidate() method. This is because the order in which components become awake is not deterministic, and therefore can result in unexpected behaviour such as the tag being overwritten when it is awoken. If you try this, Unity will generate a warning reading "SendMessage cannot be called during Awake, CheckConsistency, or OnValidate".

See also GameObject.CompareTag.

using UnityEngine;

public class Example : MonoBehaviour
{
    void Start()
    {
        //Set the tag of this GameObject to Player
        gameObject.tag = "Player";
    }

    private void OnTriggerEnter(Collider other)
    {
        //Check to see if the tag on the collider is equal to Enemy
        if (other.tag == "Enemy")
        {
            Debug.Log("Triggered by Enemy");
        }
    }
}