I have been hearing about this new product called Docker. the website doesn't really explain what it does and people that has brought it up on conversation has said it's better than VM hypervisors. yet these same people couldn't explain it further than that statement. i'm looking for a solution that is cheaper than VMs. so if Docker is a more cost-efficient replacement, I would like to know about it further before I bring it up in conversation with our management. Please help.