Communication theory states that communication involves a sender and a receiver (or receivers) conveying information through a communication channel. Their are many communications devices such as blogs, wikis, podcast and video conference.
Podcast: A multimedia digital file made available on the Internet for downloading to a portable media player, computer, etc.
Wikis: A Web site developed collaboratively by a community of users, allowing any user to add and edit content.
Blogs: A Web site on which an individual or group of users record opinions, information, etc. on a regular basis.
Video conference: A videoconference or video conference (also known as a videoteleconference) is a set of interactive telecommunication technologies.