Google Apps
Google Apps for Education, more commonly referred to as GAFE, are a host of products designed by Google for specific use in education. Many of the products you are probably already familiar with; things like gmail, Google Drive, Google Calendars, and YouTube are all part of GAFE. But in addition to all these well-known services, there are a multitude of add-ons that a teacher or administrator can add to their account to enhance the teaching and learning experience in your building.
photo credit: http://www.bwsd.k12.wi.us/