When i created an empty game object,there appeared a drop down named 'tag' showing untagged, respawn, finish, editor only etc.. whats the purpose of it?
The scripting reference for GameObject.tag says, "A tag can be used to identify a game object."
Practical implementations include GameObject.CompareTag (used for comparing the tag of a gameObject to a string argument) and GameObject.FindWithTag (used to find and return a reference to the first gameObject found with that tag.