For a start, look at the links at the top of the page: Internet Marketing > Search Engine Optimisation. Maybe a good idea to ask a question here.
Now for this pathetic question. Use google. It's a lovely site that could answer all of that in one search, and not waste our time with something you could've easily done yourself.
Post a well structured question and show you've made an effort, and we'll use all our brain power to answer it. Simple concept.