f-strings work in the same way as the format method they are just a little shorter to type. Instead of putting .format() after the text you put f before the speech marks and then fill the curly braces with the variable names or data with the same formatting codes that format uses. eg
author = "Neal Stephenson"
book = "Snow Crash"
price = 32.45435
print(f"The book {book} by {author} costs ${price:.2f}")
As we usually store all of our data in variables and don't often repeat the variable in a single print statement this makes f-strings slightly quicker to type and easier to read than the format method.
Remember that f-strings only work with Python 3.6 and later.