The most unique characteristic of Python, unlike other programming languages, is indentation. Indentation not only makes Python code readable, but also distinguishes each block of code from the other. Let's explain this with an example:

def fun():
    pass
for each in "Australia":
    pass

While writing the code, a new block of code starts with a colon followed by a tab. Here, after the function fun(), a colon is provided which will start the function body, pass is part of the function fun() and it is placed at one tab space. Likewise, the for loop starts with a colon. Here, most people get confused whether to use a tab or space. It is advisable to stick to only one type and follow the same across the whole code. If the indentation is not strictly implemented, then code execution will throw an error.