This is what SEO is:
1. Onpage optimization means optimizing your entire site to rank well in the Search Engine Result Pages (SERPS). It includes:
• Updating Website Meta Tags
• Advanced HTML Source Code Optimization
• W3C Validation and Reporting
• Image Optimization
• Body Copy Optimization
• Flash/JS Optimization
• Internal Linking & Navigation Optimization
• XML Sitemap generation and submission
• Robots.txt creation
2. Off-page optimization is done off the pages of a website to increase its performance in the search engines. It includes:
• Niche Directory Submission
• Blog Link Building (content and blogroll)
• Article Submission
• Competition/Hub Based Link Building
• Advanced Link Building
• Quality Reciprocal Linkage
• Social Bookmarking
• Classified Posting
• Press Releases
• Forum Participation
• Local Listings & Yellow Pages
• Business Reviews
• Link Baiting
• Participate on Social Networking Site like Facebook, Twitter, LinkedIn, Google+ etc