Google Drive is a file storage and synchronization service developed by Google. Launched on April 24, 2012, Google Drive allows users to store files on their servers, synchronize files across devices, and share files.
Dropbox is a modern workspace designed to reduce busywork-so you can focus on the things that matter.
Microsoft OneDrive (previously known as SkyDrive) is a file hosting service and synchronization service operated by Microsoft as part of its web version of Office.