Well what is the most important factor of onpage SEO... The factor without which onpage would be incomplete?

Search engine optimization, on page optimization factors or natural search results in your web page listings web site refers to an effect. These factors by you or are controlled by your page coding. Examples of the actual HTML code on page optimization, meta tags, keyword placement and keyword density are included.

On-page optimization involves modifying keyword frequency in the URL, Title, Headings, Hypertext Links and Body text.

Onpage optimization is the other part of seo it involves optimizing the meta tags like title,keywords,description, and placing alt attribute on img tags and using the targeted keys on the anchor tags.

on page optimisation includes all those terchniques which is applied on "webpages", like tirle tag,h1 tag, alt tag,image optimisation etc.

On- page optimization is an important SEO technique. it helps to Increase PR of your website.

Content
HTML Tags
Code Structure
Title Optimisation
Internal Linking Structure
Meta Tags Optimisation
Alt Attributes
Keyword Optimisation & Synonyms
Image Optimisation
Link Optimisation

these are the best on- page optimization factors....

On page optimization is the preparation of the actual pages of the site. Search engines are an attempt to provide users with the most relevant sites for any given query. Perhaps your web site has a lot of material relevant to the search for your product, but can not be designed or written in a way that is the search engine friendly. Correct design errors and re-writing the text location and identification tags is what is known on page search engine optimization ..

On page optimization plays an key role in determining your search engine and the success of your SEO campaign. This should be done with absolute care and precision, not to lag behind its competitors in the search rankings. Several factors influence the optimization of the page of your search positions.

Onpage optimization is the process by which various elements on an individual web page are structured so that the web page can be found by the search engines for specific keyword(s) or keyword phrases.On-Page factors are related directly to the content and structure of the website.

seo company india

There are two parts in SEO, such as onsite seo and offsite seo.
Onsite SEO - Here you have to consider about the keywords, meta description, content and etc.

It deal with all type of Mata tag H1/H2, Descriptions and keywords and all other attributes.