OneDrive is Microsoft's storage service for hosting files in the "cloud." It is available for free to all the owners of a Microsoft Office 365 account (you). OneDrive offers users a simple way to store, sync and share various types of files, with other people and devices on the internet.
OneDrive is already installed on your machine (part of the Office 365 bundle Mercer deployed) and is being used now on your computer and is already setup. Every time you save a file to the computer it is saved to your OneDrive folder and synced to the cloud. You already have the ability to retrieve your files remotely when you sign into your Office 365 account (link on the portal).
If you need some help getting started with this tool I have included a video https://youtu.be/hkf1p1Y6rFQ - Beginner's Guide to OneDrive for Windows.
OneDrive and Collaborate video (video 52:21) - Mercer Online overview of the Ondrive and Collaborate tools.