TypeError: argument 1 must be pygame.Surface, not JpegImageFile code example

Example: TypeError: argument 1 must be pygame.Surface, not str

Traceback (most recent call last):
  File "Tutorial 5 First game.py", line 26, in <module>
  screen.blit("back.png", (0,0))
TypeError: argument 1 must be pygame.Surface, not str