Web 2.0 can be defined as the online tools used in order for people to connect and communicate with one another. Teachers should know about it because it is a good way for them to communicate both with each other and with the student's parents. It's a good way to help teachers work together and to keep parents involved.
A Blog is an online journal which allows people to share their stories and ideas with others. Every teacher should have one because it is a great way to capture the student's attention. It's something that they're in to and can be used in the classroom to complete assignments as a class or in groups. They can learn to work together while having fun!
First of all, blogs can be about a number of different topics. Student driven blogs can be about anything and might even be just for fun between friends whereas a teacher-created website focuses on certain subjects being taught in the classroom, for the students.