Twitter is the most common PLN out there. With thousands of teachers out there you can find help easy using hashtag searches. Using tweetdecks and other awesome resources available.

This PLN allows you to find great ideas and also share ideas with teachers everywhere and you don't have to follow the person. However the more people you follow the more ideas will show up. You also have the option to pin something which saves it so you will always have it.

Facebook is harder to find trends and new followers, if you have a good list of teachers on your friend list then it is a great resource to answer long questions using facebook messanger.

Youtube allows you to look up anything that you can use for your classroom. People post instructions on how to do anything. So for the use of PLN a teacher would just have to type in a certain question and instantly have hundreds of videos to watch for answers.

Skype allows you to have face to face conversations with multiple people around the world. If you are a very busy person this PLN allows on the go people to chat with big name people at anytime.