Search:

Blog is online journal which is help to other people.add new material to or regularly update a blog.

SEO:
search engine optimization is the process of keep changing the the position on search engine. we can rank website by organically.
SEM:
search engine marketing is paid marketing.

Important Off-page Optimization activities:

1. Creating Quality Content
2. Social Bookmarking Sites
3. Blog Directory Submission
4. Forum Submission
5. Blog commenting
6. Classifieds
7....

1.Get your keyword research on.
2.Put the keywords to work.
3.Write about something people care about.
4.Know the basics of technical SEO. ...
5.Make it long enough to count.

On-page and Off-page are two main factor of seo.

Canonical URL can help to better inform search engines which URL have duplicate content.

Blog commenting is the easiest way to get backlink on website. To leave the text with your site URL on third party website blog, to get backlinks.

Quality backlink improve website ranking on google. so its very helpful in SEO technique.

SEO is purpose is simple, to grow your business website traffic & rankings to increase sales. its also help for growing business online increase audience, traffic.

There are many tools are available on google. all are given bellow:
1)Mozbar
2)SEMRUSH
3)Google keyword planner
4)Ahrefs