SEO 301 & Canonical

301 Direct is the Greyhound bus to Chicago, and a Canonical attribute is another way of referring to what a well hung Bishop is most proud of.

301s pass value from one defunct page to the new page, canonicals are a sticking plaster for bad code and architecture.

In 301 redirection is permanent redirections, Google crawl this url

A 301 Redirect signals to the search engine that the page has been moved permanently, remove the page from the index and pass any acquired SEO credit to the new page. Where a Canonical Attribute signals to the search engine that the document has multiple versions of the page (or its content). The URL pointed listed in the canonical attribute should be consider the original, the real page: only it should be indexed.

301 redirection means it is permanent link redirect. So to avoid the canonical issue 301 redirection we using..

301 tells Google that the page has been removed permanently. Canonical is not actually a redirect. It's used when there are multiple versions of a page or document and you want to tell Google that this is the page that should be indexed.

301 is permanent the permanent redirection. It is most effective and search engine friendly redirection.
A canonical tag is a way of informing search engines that a specific URL represents the master copy of a page. With the canonical tag you can prevent problems caused by identical or "duplicate" content appearing on multiple URLs.Example of canonical tag:
<link rel="canonical" href="a.href">
here rel and href are the attributes of this canonical tag.

301 Redirects are primarily designed for more permanent complicated jobs.

- Expired content
- Multiple versions of homepage
- Change of site

Canonical tags are a better way of telling Google that a query or slash is serving the exact same page content and is just a variation of the URL. Neither if done correctly will have a negative effect on the SEO, however using the canonical tag is far easier and appropriate.