Linking Wikipedia articles together is very important. These easily created links allow users to jump to information related to the article they are reading, greatly adding to Wikipedia's usefulness.
When to link
Adding links to an article makes it more useful, but too many links can be distracting. To avoid overlinking, you should normally create a link in an article only at the first occurrence of a word or phrase (thus, lead sections of articles often have more links than other sections). You should not link common words such as "state" and "world", even though Wikipedia has articles for those words, unless these common words are central concepts to the article.
How to link
A video tutorial about the basics of wiki markup, including creating links
To make a link to another Wikipedia page (called a wiki link), put it in double square brackets, like this:
which the reader will see, after you publish your edit, as this: Sandbox
If you want to link to an article, but display some other text for the link, you can do so by adding the pipe "|" divider (SHIFT + BACKSLASH on English-layout and other keyboards) followed by the alternative name. Place the article you want to link to before the pipe divider, and the text to be seen after the pipe divider. Two examples:
[[Fox Broadcasting Company|Fox]] In the finished article, the text will read 'Fox', and link to the article called 'Fox Broadcasting Company'.
[[Queen (band)|Queen]] and
[[Queen (chess)|Queen]] will both display as Queen, but link to very different articles.
You can make a link to a specific section of a page like so:
[[Target page#Target section|display text]]
will display as this: Categories
If you want the display text of the link to appear in italics or bold, nest the double square brackets for the link within the multiple apostrophes that delimit the italicized or bold text, like this:
''[[War and Peace]]''
which will display as this: War and Peace
Please check your links to ensure they point to the correct article. For example, Apple points to the article about the fruit, while Apple Inc. is the title of the article about the consumer electronics manufacturer. There are also "disambiguation" pages, which are not articles, but rather pages which contain links to articles with similar titles. Some, such as Apple (disambiguation) are obvious, while others such as Georgia use generic titles. These differing titles are where piped links are especially useful. For example, a wikilink of Georgia (country) is much less readable than a piped link of Georgia, though both take the reader to the same place.
You can also put the article in a category with others in a related topic. Near the bottom of the article, type [[Category:]], and put the name of the category between the colon and the brackets. For example,
It is very important to put in the correct categories so that other people can easily find your work. The best way to find which categories to put in is to look at pages on similar subjects and check which categories they use. For example, if you write an article about a type of tree, you may look at an article on another type of tree to see which categories could be appropriate.
To add a new external link, just type, inside a single set of brackets, the full URL for the link, followed by a space and the text that will be visible. For example:
[http://www.example.com/ Official website]
will display the following, whilst linking to the full URL:
Links can be added through the menu, or by using the shortcut Ctrl+K.
Using the linking menu or shortcut creates a dialog box that allows you to search for relevant internal links within Wikipedia. Pressing ↵ Enter or the "Done" button causes the link to appear on the VisualEditor page.
External links (to other websites) can be created using the "External link" tab, and entering a URL in the box. In articles, this is generally appropriate only in the External links section, at the bottom of the page.
Note: To view this information in an article style format, see contributing to Wikipedia. Wikipedia also has "topic specific tutorials"; and The Wikipedia Adventure a comprehensive and fun 7-mission interactive guided tour, which covers all the essentials about editing and the expectations and norms of the Wikipedia community.