Following files is an easy way to keep your own personal list of interesting files visible in one place, event though they may live in different libraries or sites.
In OURDrive, you can mark a file to follow by selecting it and pressing the Follow button in the Share & Track section of the Files tab in the ribbon.
A confirmation window appears in the top right corner.
Once you have done this, the file goes to your OneDrive for Business. To get to this, click on the OneDrive link in the top right corner of the window.
In OneDrive for Business, click o the Followed Documents menu heading on the left edge of the screen.
Any documents you marked as Follow will appear there. Use the Stop Following link to remove them.
Also note related documents suggested to the right.