The spaces at the beginning of a code line is called as Identation.

In other Programming languages Identation or Spaces in the beginning of the code if just for readability but In Python it makes difference. The indentation in Python is very important. Python uses indentation to indicate a block of code.

For Example:

if 5 > 2:
  print("Five is greater than two!")

In above example when you make identation before print statement after IF statement, it is considered as the code block for IF statement.

and

if 5 > 2:
print("Five is greater than two!")

the above code will give you syntax error.