Does iCloud Drive include local file mirroring
I'm running Yosemite on a new MacBook Pro and I recently updated my iCloud space to 1TB and then uploaded about 200 GB of video files, but the transfer of files didn't appear to affect the local storage report on my MacBook Pro HD (under "About This Mac" - Storage - "Macintosh HD". In fact my stated space available got smaller after the transfer.
I'm wondering if iCloud Drive keeps a mirrored copy of the files locally like Google Drive and Dropbox do?
In which case I should probably find a different storage medium if I want to free up the HD space as I had intended.
Anyone know the answer to this?
OS X Yosemite (10.10.1)