There are two type of SEO:
1. On Page SEO
2. Off page SEO

 Black hat SEO refers to the use of aggressive SEO techniques that focus only on search engines and not a human audience and usually does not obey search engines guidelines.

Benefits of SEM (Search Engine Marketing) Increase brand awareness and brand equity of product with website traffic.

Microblogging is a part of blogging and instant messaging that allow users to create and post short messages with an audience online.

Classified is off page seo techniques used to get quality backlinks and traffic on a website.

Top 10 off page seo techniques to reach on first page in SERP:

1. Article submission
2. Blog commenting
3. Blog posting
4. Social bookmarking
5. Business listing
6. Slide sharing
7. Forum Postings
8. Image sharing
9. PDF/PPT sharing
10. Micro blogging
Off-Page:
Search submission
Web 2.0
Social bookmarking
Classified Ads posting
Social media like Facebook,twitter,plus google,linkedin
directory submission
article submission
forum posting
guest posting

Alexa rank is the ranking of your website in the search engines is an analytics tool that provides traffic metrics for your website.

Keyword density is the most important SEO factor, but it's easy to overdo and be penalized by Google.

Broken links are links that lead to pages that are not exist or removed. When clicking on a broken link, the page you land on is called a 404 page.

An impression is a view. When your ad or website loads and displays in front of user, known as impression. A click, simply enough, is whenever a user actually clicks on your ad or website.

SEMrush is the best tool for initial seo audit

Business listing is an online entry that contains your business Name, Address and phone number along with other details.....

There are many free tools to get competitor backlinks like backlinkwatch.com, semrush.com etc.

Dofollow links allow google to follow them and reach on website. Giving us link juice and backlink. If a webmaster is linking back to you with this link both Search Engine and users will be able to follow you. The best way to give dofollow love is allowing keyword in the anchor text.