Do i need to use canonical tag on each page of website (Newbie in Seo)

[seigell971]

What happen when you put canonical tag in a web page?

It tells google to index the canonical urls if any duplicate page found. Suppose your website have 5 pages of similar information. Then how will you decide to index a particular page among all 5 pages. You can easily tells google to index a relevant page by putting canonical url on it. Then, google leave the remaining pages and index the one page you choose.

[pablito]

If your blog posts' canonical points to the homepage, Google treats them as dupes and quietly drops them from indexation. Your content turns into thin content in the crawler's eyes, and your backlinks go to waste.
Put a self-referencing canonical on every post, and learn the basics before touching the head section.

[10xlinks]

Short answer for a newbie is yes, give every indexable page its own canonical, and point it at itself. That is the safe default and it protects you if the same page ever loads under a tracking parameter, with and without a trailing slash, or on both www and non-www. Where it really matters is when you have near duplicates, like filtered category pages or printer versions, because there you point them at the main version. The mistake to avoid is a template that hardcodes one canonical, usually the homepage, for every page, since Google may then ignore your other pages. After setting it up, open a few pages with view source and check the tag shows the right address, then use the URL Inspection tool in Search Console to see which canonical Google actually picked.

[NickRanker46]

One mistake I see a lot with beginners: a theme or plugin setting that points the canonical of every page to the homepage. Then Google may just ignore the inner pages. Worth opening a few pages and checking the canonical in the page source.