Why use df["column":].str as opposed to not

Question

If I have a dataframe with a string column and I want to do some filtering, what's the difference between

df["string_column"].str.startswith(...)

and

df["string_column"].startswith(...)

Both work fine for me. I'm just curious of why we use .str

Answer 1

some methods are specific to string types only. such as contains(), lower(), replace()..