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.
As you can see, a VPS can be the perfect middle ground for many – enough flexibility and resources for those who need more access or control than on a shared server but without the cost of a dedicated server. If you need root access, you can’t get that on a shared server, but you can get it on a VPS. If your site experiences unpredictable swings memory usage, and your host provides it, then the presence of burstable memory will be attractive. And, if you’re a fan of customization, then the fact that you can customize server-level software such as PHP, MySQL, and Apache will perk your interest. In short, choosing a VPS will allow you to have many of the same characteristics of a dedicated server but in a more affordable and manageable package.