What does this ImportError means?

Question

    import os
    import sys
    import math
    import time
    import pygame
    current_path = os.getcwd()
    import pymunk as pm
    from characters import Bird
    from level import Level

ImportError: cannot import name 'Bird' from 'characters' (C:\Users\Xtreme Tech\AppData\Local\Programs\Python\Python39\lib\site-packages\characters_init_.py)