Barebone are computer kits with just the cabinet, motherboard and processor (depends on the kit) Something like a starter kit. Its good if you want to configure it to your needs, add a gpu of your choice, water cooling etc. That's why they are cheaper.
The kit you have there only has the Cabinet, motherboard(with on-board graphics), processor, ram and hard drive. You'll have to get a graphics card and optical drive if you want a mid-end gaming setup.