Please tell me which SEO factors can not in our control?

What is the difference between a do-follow and no-follow and how are they used?

Please describe the relationship between SEO and SEM?

What are backlinks ?

What is Google Crawling ?

What is Web 2.0 ?

Can anyone tell me about google adwords planner.?

What do you know about SEM.?

Can anyone tell me about social Signals and how it is useful?

Can anyone tell me what is a effect of SMO

What is apps marketing useful strategies?

What is twitter summary card.?