A data center is a place designed specifically to host computing systems, such as server computers and data storage arrays. Many data centers are run as services, which allow customers to rent rack space that they can use to install computing hardware that they own, which is known as co-location.
Data centers are built with features designed that help ensure the continuous operation of the computing hardware installed inside. These typically include redundant power circuits and local backup power generators, air conditioning to keep equipment cool, fire suppression systems, connectivity from multiple internet backbone providers, remote hands services and secure entry systems.
A large data center can contain thousands of computing devices, and consume as much electricity as a small town. Whereas there are only a handful of large cloud computing services, such as Amazon Web Services, there are thousands of independent data centers around the world where you can install your own computing equipment.
The Internet Computer blockchain is hosted by dedicated node machines installed in data centers. This means that it has a sovereign network, whereas most blockchains run in the cloud.