or if you need it better in plain english see below:
Some Social Networks that as a teacher you may know are Facebook, Twitter, or Linkin. The one that we are trying so hard to get teachers to develop both inside and outside social networks is Twitter. With Hashtags teachers have the ability to look up other people that are interested in a common theme. The sharing of material, opinion and research on line is phenomenal.
The video below explains about Twitter Search in Plain English. Hopefully, this will show the importance of using Twitter in PLNs to my colleagues.