Microsoft's OneDrive (née SkyDrive) is, quite literally, a virtual disk drive in the Cloud and one that you can save files to and load them from, with very few restrictions - and it's all beautifully integrated into Windows Phone and now Windows 10 (Mobile). And it's pretty good on Android too.
But, though it's simple enough on the phone, there's a big decision to be made on your comparison Windows 10 tablets and laptops/desktops. There's the Win32 traditional OneDrive sync client, keeping all files synced and uploaded and downloaded as needed - and then there's the UWP app, providing a windows into the Cloud drive, from where you can grab stuff as needed, with no need to allocate Gigabytes on your computer.
From Mauro Huculak's article over on WC:
In either case, you need to download those files you want to have available offline, but it's likely to work better with the desktop version, as you must select the files that you want to sync during the initial setup.
If you choose the OneDrive Universal app, you also need to consider your internet connection speeds. If you're on a slow connection, it can quickly affect speeds performance, or when you're on a metered connection, depending on how you use the service, you will increase your chances of hitting your data cap.
People using tablets or 2-in-1 devices with limited storage are probably the ones able to take more advantage of the new OneDrive Universal Windows Platform (UWP) app, because of the ability to save some space on their hard drives, and the touch-friendly UI that makes much easier to navigate and work with files.
On the other hand, if you use a desktop PC or a laptop, you'll notice that many features are still missing in the Universal app. Also, there is a chance one day you'll forget to sync those files you need to complete your work, and there isn't an internet connection nearby -- something that isn't likely to happen with the desktop client. However, you can always use the new OneDrive app as a companion app as you can connect multiple accounts and view all your files stored in the cloud.
While both solutions aim to provide access to your files stored in the cloud, as you can see they offer different approaches trying to accomplish the same thing. But don't forget that the Universal app of OneDrive is still in its early days, even though it's out of beta. Microsoft has previously said that it will continue to work to improve the app with future updates.
You can read the whole thing at Windows Central here. It's a somewhat 'nuts and bolts' set of pros and cons, but still a useful reminder about the decision that each person will need to make for each device. Usually based on local capacity, but also on network speed, as mentioned above.
Personally, the natural split is for the OneDrive desktop sync client for laptops and computers with hard disks (i.e. usually 256GB plus) and the OneDrive UWP for netbooks and tablets with less storage than this - plus phones, of course.
Your comments welcome - how do you fit OneDrive into your phone/tablet/computer workflow?