Seo stands for Search Engine optimization. the Seo is two Type:-
1.On Page optimization.
2. Off- Page optimization.
On page optimization types:-
- Content optimization.
- Meta tag updation.
- Keyword analysis.
- Alt tag.
- Html and Xml stemap.
- Robots.txt file.
Off page optimization:-
- Directory submission.
- article submission.
- Blog commenting.
- book marking.

Good functionalities of SEO you have listed by dividing into ON page and OFF page. talking about its future then we can say that now Google is launching strict algorithms so that spam work can be totally removed. Now webmaster would have to do quality work so that their website can be protected from being penalized.

Yes, the Google algorithim changes and the Panda as well as the Penguin udates have hit many very hard. Any techniques that are now considered spam can hurt your rank, even though some of those methods were sound in the past. The really sad fact of the updates is that many techniques that were considered solid SEO are now coming back to haunt webdesigners and SEO experts as well as the companies that they work for. Even if you are using the best methods for today it is no guaranteee that the techniques will last forever. Be ready to adapt.