"I've heard some people say footnote, and other people say bibliography. What's the difference?"
Footnotes and bibliographies are linked to each other. When you cite a source, you're providing credit for that source in two different places: a footnote and an entry in the bibliography.
Bradbury, Ray. Fahrenheit 451. New York: Ballantine Books, 1970.
The information in the footnote should always match the bibliographic entry. That way, if a reader wants to find more information about a source while reading your work, s/he can just flip to the back to locate the source in your bibliography according to the information you provided in your foonote.
It's also a good idea to double-check that all of the sources in the footnotes are in the bibliography, and vice versa. In other words, don't include sources in your bibliography that you didn't quote or paraphase; that's called "bib padding."
Citations (footnotes and bibliographies) perform very important roles in research, both at an academic and a professional level.
Why Should I Cite?
Citing your sources
When Should I Cite?
You should use citations whenever you quote, paraphrase, or summarize someone else's work.
You should cite your sources whenever you write ideas that aren't your original ideas. For specific situations, take a look at: Plagiarism Resources.
While there are different citation styles (APA, MLA, Chicago, etc.), they all serve the same purpose. And they all have similar fill-in-the-blank properties. Think of them like jigsaw puzzles. You just have to put the pieces together. And just as different jigsaw puzzles are completed in different ways, different citations have different orders of placement.
citation jigsaw puzzle solved
citation jigsaw puzzle pile
Also, syntax and punctuation matter in the creation of citations. If you place the citation elements in the wrong order with incorrect punctuation, the citation won't work — just as the jigsaw pieces wouldn't fit together if the shapes or edges weren't exact matches.
All bibliographic entries provide the same types of information: