The same blog content can be present in different parts of the web, say, in dev.to, medium.com and your personal website. Search engine ranking will be harmed if multiple pages has the same content. To avoid this, canonical URLs can be added to the replica pages (say, dev.to and medium.com) which will point the original content (your personal site). So that search engines can organize their search results without harming the ranking.
So I have setup my blog in github pages, and I am all setup with Jekyll.
This might be a silly question, what is a canonical_url used for?
The same blog content can be present in different parts of the web, say, in dev.to, medium.com and your personal website. Search engine ranking will be harmed if multiple pages has the same content. To avoid this, canonical URLs can be added to the replica pages (say, dev.to and medium.com) which will point the original content (your personal site). So that search engines can organize their search results without harming the ranking.
For more info, refer: yoast.com/rel-canonical/
Awesome, thanks for the detailed info!