Basically two types of SEO as below:
1) On Page Optimization
2) Off page Optimization
On Page SEO Means inside of the website like site title, meta description, meta keyword, keyword research, On Page Search Engine Optimization has been around the longest time, since the beginning of search engines. Search engines use simpler less sophisticated technology a few years ago and the world wide web was a more smaller. At the time on Page SEO Worked years ago and it was basically an easy compare. As the world wide web grew larger and larger it became more difficult for search engines to differentiate between your site & other sites. A search on Autos may return 100 million + pages that have the word Autos on it. So off page SEO began to take off as the world wide web and search engines.
On Page Elements:
On Page Elements refer to the html tags within the page. including Heading tags (<H1>) , Bold tag , Title tag, Italic tag on your web site. Below is an example of phrase “SEO Company” used in a Heading (<h1>) and Bold (<b>).
Off Page Search Engine Optimization has been become probably the most important factor about how your site ranks in search engines. The internet and world wide web continues to grow and grow at an enormous rate. Pages of similar topic apparently arise. There might be 100 million web pages/site on the topic of baseball or 100 million web sites on the topic of web site design and search engine programming. Because of this highly large database of similar contents, search engines begin focusing on off page SEO factors in determining relevancy of search results.
Off Page Factors:
Off Page Factors are factors outside of your normal control of the content of your web site. They are frequently referred to by search engine optimization experts as the “inbound links” your site receives from OTHER websites such as guest blog post services. It’s like a popularity of contest that search engines factor in how many other websites visit your site, thought the information was relevant to their site and “linked to you” .