What is Onpage Optimization And Off page optimization

On page optimization
1.Title
2.Meta Tags
3.Bold Font
4.Alt Tags
5.Alt Image
6.Header Tag

Creating Xml
Checking Website load time spelling(etc)
Implementry Checking Codes all the pages
Checking and Broken links on the Website

Off page optimization
1.p.p.c
2.Link Popularity
And
Articles
Blogs
Forums
Press Releases
Rss feeds

Writing and publishing articles
Submit update pinging blogs
Writing and publishing press releases