What is a datacenter?
A “datacenter” is a data processing center, that is a physical or virtual infrastructure used to host computer systems that can process, serve or store data.
For a “datacenter” function properly, it must follow several important guidelines, based on security, connectivity, energy, air conditioning and storage:
▸These environments usually have special air conditioning to prevent the machines from overheating.
▸In addition, there must be a reliable power supply that can keep the equipment active at any time.
▸There must be security protocols that combat all kinds of situations or problems like natural disasters or virtual attacks.
▸Continuous monitoring of equipment is needed to prevent its fall or a failure that significantly affects access to data.
▸Distribute the racks appropriately. Let’s not forget that racks are metal supports with a shelf-like appearance that are used to keep electronic, communications and computer equipment.

ANSI/TIA 942
This classification called ANSI / TIA 942, aims to certify the availability of the components that these buildings have. For example, size, levels of redundancy, response times.
All of the above is measured in four levels, which are called TIER and the higher these are, the more reliability they provide.

▸TIER 1: This class is made for small and medium businesses. Here the service can suffer interruptions, since it does not have a refrigeration system or electrical distribution. The average implementation time is three months and to carry out maintenance work, it will be necessary to stop the activity.
▸TIER 2: This is less susceptible to interruptions, planned or not, with connection to a single line of refrigeration and electrical distribution. Its implementation tends to take 3 to 6 months and it has raised floors, auxiliary generators or UPS. If maintenance work is carried out, the service must still be interrupted.
▸TIER 3: This type, in general, provides services 24/7 and is connected to multiple electrical distribution lines and refrigeration, although with only one active. Of course, for its maintenance it is not necessary to stop the operation of the system, since the capacity is ideal to provide the service through other lines. The implementation time is much longer and ranges from 15 to 20 months.
▸TIER 4: It is aimed at companies with an international presence, such as banks and multinationals. It is fault tolerant as it allows multiple lines of electricity and cooling distribution. Maintenance can be done without affecting service and can respond to unplanned events. Its implementation can go up to 20 months.

A very widespread option today is the “virtual datacenter” or “cloud storage”. This solution avoids companies dealing with the technological complexities of implementing their own physical “datacenter”. In addition, it is the cheapest alternative, since you only pay for the resources consumed.
Today “data centers” are crucial in providing IT and storage, communications and networking services to the growing number of networked devices, users, and business processes in general.
More information on here: https://en.wikipedia.org/wiki/Data_center