A data center is a facility that contains a large number of web servers. The servers can be used for numerous purposes - hosting, file and picture storage, computing, etc. All bigger companies which supply online services have their machines in one or numerous data centers as such a facility can supply the necessary environment and security for the information stored on the machines. Including environmental settings for the temperature and humidity in order to guarantee the optimum performance and long life of the hosting servers, backup power generators, hardware monitoring and last, but not least, physical security and safety as to ensure that that your info can't be accessed by an unauthorized third-party. A badly performing data center may very easily undermine the services a business supplies.