OpenVZ virtualization is an OS level container-based virtualization, and it has resources that are divided between users on a physical server. Each container acts like a stand-alone virtual server and can be accessed with a root (SSH) connection. As a separate server container can be rebooted separately, it also has a dedicated IP address, shared RAM, individual processes, files, applications, system libraries and configuration files. On OpenVZ, the kernel cannot be modified. It has its stable version and modules cannot be added. The good thing regarding this virtualization is a faster performance, and a lower need of resources.
Unmetered hosting is generally offered with no limit on the amount of data-transferred on a fixed bandwidth line. Usually, unmetered hosting is offered with 10 Mbit/s, 100 Mbit/s or 1000 Mbit/s (with some as high as 10Gbit/s). This means that the customer is theoretically able to use ~3 TB on 10 Mbit/s or up to ~300 TB on a 1000 Mbit/s line per month, although in practice the values will be significantly less. In a virtual private server, this will be shared bandwidth and a fair usage policy should be involved. Unlimited hosting is also commonly marketed but generally limited by acceptable usage policies and terms of service. Offers of unlimited disk space and bandwidth are always false due to cost, carrier capacities and technological boundaries.