A data center rack is a physical steel and electronic framework that is mainly designed to house servers in different form factors such as – blade servers or rack-mounted. Although it’s primarily designed to house server, some racks are designed to accommodate other equipment such as networking equipment, UPS, telecommunication equipment and cooling systems as well.
Normally, all racks are pre-fabricated with slots for connecting electrical, networking and Internet cables. They’re created following a systemic design, and are categorized based on their capacity or the number of bays – essentially, the amount of resources they can hold.
Racks are divided into regions – 1.75 inches height, wherein there’re three complete hole pairs in a vertically symmetric pattern, the holes being centered 0.25 inches, 0.875, and 1.5 inches from the top or bottom of the region. Such a region is commonly known as a U, for unit.