BLOGS
Blogs are a special type of web page. Many blogs are opinion generator about a variety of topics. Other blogs are used as 'online diaries' for people.

Bloggers publish entries in chronological order, with newer posts appearing at the top of the list. People can write a comment with their opinion as well.

Tumblr, Wordpress and Blogger are some of
the most popular weblogs.

WIKIS

A wiki is a collection of web pages that visitors can edit, modify or expand.

 Adding new content to a wiki page is easy:

Other example of wiki

1.-Click in the Edit button.

2.-Write a new contribution.

3.-Click in the Save button.

An example of wiki

WIKIPEDIA

Wikipedia is a universal encyclopedia with no restrictions on use, modification or redistribution. Anyone can contribute their knowledge to this project.