In short, interlinking is when you hyperlink a word or phrase to another page on your website to provide the reader with further information surrounding a topic.
For SEO best-practices, follow the 9 tips below: (note: see how “SEO” links to another page? That’s an example of an interlink)
Tip #1: Add internal links when deemed useful for the user
Example: A blog post talking about the importance of having a content strategy linking to an internal service page on content creation and/or an internal blog post talking about how to create a winning content strategy.
Tip #2: Variation in internal links is always recommended
Example: A blog post talking about the importance of having a content strategy would link to an internal service page on content creation with the Anchor text “content creation” or “this page” or “this service”. If you cannot use keywords within a sentence for the internal links you can always add them as additional reading.
Tip #3: Try not to use more than 6 internal links, and not more than 4 external links per 1,000 word page/post (within the body text).
Note: This is not a “Google rule or guideline”, just my own professional recommendation.
4. Make sure that you don’t link to broken/404 pages (always double-check the pages you link to)
Note: Linking to a broken page can seriously hurt your rankings.
5. Link related pages together, don’t just link to any page for the sake of internal linking. Link to pages that are relevant to the content and/or are for guiding the user to take an action.
6. Make sure that the pages you want to rank higher in search engines have a greater number of internal links.
7. Hyperlink actual text, not images.
Note: Images don’t seem to be useful to use as interlinks for either search engine crawlers, nor Google
8. Internal links in WordPress are defaulted to “follow”. Don’t change that by manually changing the setting of an internal link to be “nofollow”.
9. Don’t place an external link before an internal link in an article. Google weighs the first links they crawl as the most important – no need to give away link power to other sites before your own.