What Is a Data Center?

Unlike an ordinary server room, a data center is a complex facility that combines IT equipment with extensive engineering and support systems designed to meet stringent availability and fault-tolerance requirements. Its core infrastructure typically includes guaranteed and/or uninterruptible power systems, including UPS units and diesel generator sets; cooling systems; server racks; and structured cabling for installing and connecting IT equipment in the data halls.

Data centers are also equipped with physical access-control systems, monitoring platforms, gas-based fire-suppression systems, video-surveillance cameras, and other protective technologies. Because a data center is designed to operate continuously—24 hours a day, 7 days a week, 365 days a year—reliability is a critical parameter. It is determined largely by the redundancy architecture used for essential engineering systems, such as N+1, 2N, or 2(N+1). The fault-tolerance level of a data-center facility is generally assessed using a four-tier system, often designated with Roman numerals. Tier IV is the highest level and is designed to tolerate individual equipment failures or interruptions in distribution paths without affecting IT operations. Data centers are the foundation of the Internet and virtually all large-scale cloud services worldwide.