Density is a characteristic which tells how many containers (CTs) or Virtual Machines (VMs) virtualization technology can run successfully on a given hardware. Density very much depends on:* virtualization technology used (containers or hypervisor);* features provided by the technology (page sharing, ballooning, memory overcommitment support etc.);* workload itself. Virtualization is not a miracle and can't handle more high loaded workloads then bare host can. e.g. do not expectany density except for 1VM/CT if you are running Oracle with huge request rates. On the other hand, if you are having multiple small web sites virtualization can easily consolidate them on a single host as long as host is capable to handle IO requests altogether and memory/CPU demands. Typically users also care for quality of service of their software, i.e. how well their services are working on utilized node and how fast they respond to external requests. Typical The metrics of quality of service are average /min/max response time, 99.9% requests response time, and max response timesimilar. When a hardware node is capable to handle the load, these metrics either do not grow much with bigger number of containers, or grow linearly. When a hardware node becomes over utilized, these metrics typically start to degrade exponentially (due to memory swap out).