Fedora 21 Cinnamon is a fedora 21 spin featuring with Cinnamon Desktop environment 2.4.5 as default desktop. it also included with kernel 3.18 and default application such as firefox 35, nemo 2.4, libreoffice 4.3, shotwell 0.2, yum extender as default sotware manager and cinnamon system settings.
Cinnamon is a Linux desktop which provides advanced innovative features and a traditional user experience. The desktop layout is similar to Gnome 2. The underlying technology is forked from Gnome Shell. The emphasis is put on making users feel at home and providing them with an easy to use and comfortable desktop experience.
More details about Fedora 21 cinnamon spin you can read on Fedora Cinnamon Spin