One reason I love Chrome OS is it lets me store and access all my data in the cloud. All I have to do is sign into my Google account from any Chrome OS device.
Well, I store in the cloud almost all my data. I save to the local storage temporary files such as screenshots or downloaded items I later delete or transfer to the cloud. If you want to go all in on the cloud, you can configure Chrome OS to keep there also the stuff on the local storage, as one article linked below explains.