OneDrive vs. DropBox
OneDrive offer more free space than DropBox. Just 2GB free space of DropBox has no comparison with 15GB free space of OneDrive. After achieving referral target, DropBox increases free storage space up to 16 GB, which is already offered by OneDrive without any effort.

Key Differences
OneDrive offer more free space than DropBox. Just 2GB free space of DropBox has no comparison with 15GB free space of OneDrive. After achieving referral target, DropBox increases free storage space up to 16 GB, which is already offered by OneDrive without any effort.
In all operating systems and mobile phones both OneDrive and DropBox are playing well. But cloud storage service of OneDrive is also available for Windows phone which is not provided by DropBox.
DropBox is more secure than OneDrive. Its verification process is very strong than OneDrive. Demand of secondary email address weakened the security system of OneDrive.
Maximum 10GB file size is limit in case of OneDrive. While there is no restrictions of file size in case of DropBox either you save file through desktop or mobile. There is only restriction of 10GB, if you upload your file through official website.
Editing features of OneDrive are outstanding. Online MS Office feature of OneDrive provides wide varieties of editing tools to users. They can easily edit their important files on website. Editing tools of DropBox are consists on basic word editing tool. If you want to edit your file with latest features, you have to install multiple apps for DropBox, which is in itself a complex task.
Speed of DropBox in accessing and sharing the data is much better than OneDrive.
OneDrive and DropBox Definitions
Dropbox
A box wherein objects can be deposited by one person for later collection by another.
Dropbox
(computing) A computer folder to which files may be dragged and dropped and from which users of other computers on the network can access those files.
Dropbox
(sewing) An enhancement to a loom that allows patterns of multiple colors to be woven from the same loom.
What is OneDrive?
On August 1, 2007, Microsoft launched the online data storage service for its users. Previously its name was SkyDrive, which was renamed as OneDrive on January 27, 2014. Currently it is dealing in all kind of data storage and sharing. Moreover Microsoft is providing 15GB free space to all users. If you wants to edit your documents, online MS Office with major parts, Word, Excel, Power Point and One Note facility is also available. Two kinds of OneDrive are available. Simple OneDrive for Windows 7 & 8 and OneDrive for Business for Windows 7, 8 & 8.1. OneDrive is available for Windows, Android, Mac OSX, iOS, Windows Phone and Xbox in 107 international languages. After installing its app or software you can direct access to your OneDrive account from computer and mobile phone instead of login in to website.
What is DropBox?
In September 2008, DropBox Inc. launched its file hosting service by the name of DropBox. It is online storage service for all kind of data storage like images, documents, videos and files. You can access to your files through desktop DropBox, phones or from its official website. You can also share all your stuff to your friends and family. Making team projects become very easy through DropBox. At that time DropBox is offering 2GB free space to all its users. You can also get more space up to 16 GB through its referral scheme. More space is also available according to price package. It is available for Windows, Mac, Linux and Android, iPhone, iPad, BlackBerry and Kindle Fire.