Simply put, the button-down collar has buttons to fasten the tips of collars to the shirt. The benefit is that the collar points always remain at the right place and in the right shape giving you perfect looks all the time. The buttons also add a dash of casual looks, which makes this collar little less formal as compared to the spread collar or the straight point collar. Therefore, this is perfect for those people who prefer little casual dressing while wanting to balance it with the formal looks.