1.
Social bookmarking is a way for people to store, organize, search, and manage
“bookmarks” of web pages. Users save links to web pages that they like or want
to share, using a social bookmarking site to store these links. These bookmarks
are usually public, and can be viewed by other members of the site where they
are stored
Most social bookmark services are organized by users applying “tags” or
keywords to content on a Web site. This means that other users can view
bookmarks that are associated with a chosen tag, and see information about the
number of users who have bookmarked them. In many cases, users can also
comment or vote on bookmarked items.
Facebook
Twitter
Google+
Pinterest
Tumblr

2.
Link building is the process of acquiring hyperlinks from other websites to your
own. A hyperlink (usually just called a link) is a way for users to navigate
between pages on the internet. Search engines use links to crawl the web; they
will crawl the links between the individual pages on your website, and they will
crawl the links between entire websites. There are many techniques for building
links, and while they vary in difficulty, SEOs tend to agree that link building is
one of the hardest parts of their jobs. Many SEOs spend the majority of their
time trying to do it well. For that reason, if you can master the art of building
high-quality links, it can truly put you ahead of both other SEOs and your
competition.

3.
A blog is an online journal or informational website displaying information in
the reverse chronological order, with latest posts appearing first. It is a platform
where a writer or even a group of writers share their views on an individual
subject.
Most blogs include some standard features and structure
Main content area with highlighted or latest blog posts
Sidebar with social profiles, favorite content, or call-to-action
Footer with relevant links like a disclaimer, privacy policy, contact page.
Blogger
Medium
Penzu
Squarspace
Svbtle

4.
YouTube
Crackle
MySpace
9GAG
TED

5.
Facebook
Twitter
YouTube
Instragram
LinkedIn