Interlanguage links are links from any page (most notably articles) in one language to one or more nearly equivalent or exactly equivalent pages in another language. They appear at one or two edges of the webpage (in Monobook on the left, in Classic at the top and bottom) after Languages, and show the names of languages for which a link is available.
The interlanguage links take the following form:
[[language code:Title]]
where the language code is the two-letter code as per ISO 639-1 (English is "en", French is "fr", etc.) and titleis the article's pagename in that particular language.
For example, in the English language article for GCpedia Help, the interlanguage link looks like this:
[[fr:Aide:Pour commencer]]
In the French language article for GCpedia Help, the interlanguage link looks like this:
[[en:Help:Getting Started]]
You should not include the link to the language in which you are writing.
Note: These links are treated specially, and don't show up in the body of the text, but in a special sidebar section "in other languages" listed by language name. Technically they can go anywhere in the article source; placement does not alter the visual appearance of the links on the rendered page except for the order. However, the convention is to put them at the bottom of the wikitext.
Alternate methods to display bilingual text
Display both official languages on the same page
The {{Two column fr-en}} template creates a simple two column layout for pages that are bilingual. As coded the English column is on the left and the French column is on the right. However, this can be changed by changing the order of the code if you prefer French on left and English on right.
How to: Follow the instructions on the {{Two column fr-en}} template page.
Display language of content dependent on the user's language preferences
The <multilang> tag is used for selective text display depending on user language settings. The language of the content is dependent on the user's language preferences. Small parts of texts like in templates (where you are forced to use exactly the same template name) can efficiently and easily be made multilingual using the <multilang> tag.
<multilang> @en| English Text Section @fr| French Text Section </multilang>