A trigger detects overlap without physically blocking movement.

Enable Is Trigger on the Collider.

void OnTriggerEnter(Collider other)
{
    if (other.CompareTag("Player"))
    {
        Debug.Log("Player entered");
    }
}

void OnTriggerStay(Collider other)
{
}

void OnTriggerExit(Collider other)
{
}

Common uses:

• pickups
• checkpoints
• mission zones
• automatic doors
• damage zones