Certainly - or perhaps a few images might be clearer.
If there isn’t enough content to fill the page - eg on a login page - the default position of the footer looks silly (IMO). It will appear where the content ends:
(this is very common on lots of websites)
Using Bootstrap’s ‘fixed-bottom’ class, it looks fine (in this case, at least):
But if there is sufficient content that requires scrolling, the footer will still be at the bottom of the page:
… which is the most accurate answer to your question, and may well be what you want, but it’s not the best solution for typical websites (IMO). Generally, it’s best if the footer appears at the bottom: either if there’s isn’t enough content to fill the page or once you scroll to the bottom of the page. This is what Ben’s solution offers.