OneDrive is a file hosting service that allows you to put your data online and you can access that data from a web browser or any mobile device. Here users can also share files within their contacts or publicly too which do not require any Microsoft Account to access it. Formerly its known as WINDOWS LIVE SKY DRIVE and now its OneDrive.
The service now offers only 5GB of free storage for new users but for old users, it was 15GB which will be reduced to again 5GB. But here now you can keep your 15GB online free storage by a single click.
Initially its started by 7GB storage for one year and an additional 3GB for students.
If you are using 15GB now by January 2016 it will be 5GB unless you use this link to retain it.