Wiki a technology for creating collaborative websites, in other words its a content management system designed to allow various people to create and edit web pages without any knowledge of HTML.
Blog is a type of website that is usually arranged in chronological order from the most recent ‘post’ (or entry) at the top of the main page to the older entries towards the bottom.
Whats the difference between a blog and a wiki ?
A blog may aid in brainstorming or generating discussion on various new topics frequently or daily. A wiki, however, is less about new content every day, and more about evolving the same content over time with collabration with various people.