Differences between blogs and wikis
Although blogs and wikis can help your team collaborate without advanced tools or specialized knowledge, there are differences in how your team can use them:
Blogs Blog posts are typically written by a specific group of people who provide information and insight, such as managers, technical experts, or people with unique viewpoints or writing styles.
In some blogs, the role of the people creating the blogs, often known as bloggers, is important. For example, managers can use a blog post to explain the reason behind some policy changes, team members can describe their experiences on a special project, or
technicians can describe best practices or how something works in their own words.
The blog posts and comments are recorded in reverse chronological order. People can scroll through the posts, similar to reading a journal.
Wikis Teams usually write wikis as a collective process. After someone creates a page, another team member may add more content, edit the content, or add supporting links. The community of authors
helps to ensure the accuracy and relevancy of the content.
Wikis continue to evolve as people add and revise information. Although a version history is collected, and the history is organized in chronological order, the versions aren't displayed in journal style in the default view of a wiki.
Your team may want to use a wiki to build a collective body of knowledge or to facilitate planning, such as for a team project, a publication, or a conference.
Librarys
Document libraries are collections of files that you can share with team members on a Web based on Microsoft Windows SharePoint Services. For example, you can create a library of common documents for a project, and team members can use their Web browsers to
find the files, read them, and make comments. Users with Microsoft Office 2013 can check out and edit the files as if they resided on a local or network drive.
By default, your team Web site comes with a built-in document library named Shared Documents, which is listed on the Quick Launch bar as well as on the Documents and Lists page.
For reference:
http://office.microsoft.com/en-in/sharepoint-server-help/use-blogs-or-wikis-to-share-info-HA010378210.aspx
http://technet.microsoft.com/en-us/library/cc262215.aspx
http://office.microsoft.com/en-in/sharepoint-help/training-courses-for-sharepoint-2013-HA104030990.aspx
karim