Simple Approach

Any text that appears within <ref> tags are collected and appear in place of the <references/> tag at the end of the article. In the example below, someone created a note with a manually formatted reference.

It's a great book.<ref>Kress, Nancy, (2011), *Beggars in Spain: 
The Novella*, Rockville, MD: Phoenix Pick, ISBN 978-1-6124-2057-8</ref>

The problems with this approach are that (1) finding such references scattered among prose makes the prose difficult to read and edit, (2) should you want to change the formatting (e.g., make the title sentence case) you have to manually edit it, and (3) should you need to cite the same thing later, you must duplicate it or use the name attribute.

BTW: <ref> isn’t really about references; it’s for endnotes more generally and it just so happens most people use them for references.

Citation Templates

Wikipedia does have a referencing system via templates that are indicated via a keyword appearing within double curly braces, such as {{citation}}. (It doesn’t matter if it capitalized or not.) This permits you to enter reference data in a structured way in fields like title, publisher, and year which Wikipedia will expand and format; if it appears within <ref> tag it will also appear in an endnote.

It's a great book.<ref>{{Citation | last1 = Kress | first1 = Nancy 
| title = Beggars in Spain: The Novella | year = 2011 
| publisher = Phoenix Pick | location = Rockville, MD |
| isbn = 978-1-6124-2057-8}}</ref>

This is what citations from the VisualEditor will look like. Again, trying to edit and read wikitext in the source editor with these blobs scattered amongst the prose is awful.

Recommended Approach: Reference-defined list

If you remain in the source editor, or start with the Visual Editor and later clean things up in the source editor, I recommend you use a reference-defined list at at the bottom of the page. The Reference segregator can convert from inline to end-list for you—ask me if you need help!

Here, you use <ref name="Kress2011bsn"/> in your prose, and at the bottom include the citation templates within <ref> tags (using the same key name) within the {{reflist}} template.

It's a great book.<ref name="Kress2011bsn"/>

== References ==

{{reflist|refs=
<ref name="Kress2011bsn">
{{citation
| first1 = Nancy
| last1 =  Kress
| title = Beggars in Spain: The novella
| date = 2011
| isbn = 9781612420578
| publication-place = Rockville, MD
| publisher = Phoenix Pick
}}
</ref>
}}

To include a page number, you can complement the <ref> tag with the {{rp}} template.

This is my favorite page.<ref name="Kress2011bsn"/>{{rp|6}}

This will look like this: This is my favorite page.^[1]:6

Advanced Approach: {{sfn}}

I don’t like page numbers appearing in citations rather than the bibliography. To counteract this, you can use a similar notes at the end technique with the short-foot-note {{[sfn]}} template. This requires you to edit in the source editor most of the time, which I do, but most people don’t. If I’m going to overhaul a page and convert its citations to this format, I use the References Segregator.

I love the description of the sleepless{{sfn|Kress2011bsn|loc=p. 45}} 
and of their philosophy{{sfn|Kress2011bsn|loc=p. 78}}.

==References==

{{reflist|}}

==Bibliography==
{{refbegin}}
* {{citation | ref = {{sfnref|Kress2011bsn}}
| first1 = Nancy
| last1 =  Kress
| title = Beggars in Spain: The novella
| date = 2011
| isbn = 9781612420578
| publication-place = Rockville, MD
| publisher = Phoenix Pick
| url = https://books.google.com/books?isbn=9781612420578
| accessdate = 14 July 2016
}}
{{refend}}