Final answer:
A big group of connected servers powering a site is known as a data center. It houses numerous networked computers used to manage and store large amounts of data. Supercomputers and mainframes serve different purposes, being geared towards complex calculations and large scale data processing, respectively.
Step-by-step explanation:
The big group of connected servers that power a site is called a data center. A data center is a facility that houses a large number of networked computers and storage systems, which are used to organize, process, store and disseminate large amounts of data. Unlike a single web server that may host a website, a data center can contain many web servers and other infrastructure components such as backup systems and security appliances.
Supercomputers and mainframes, while powerful, serve different functions. A supercomputer is primarily used for complex computations and scientific research, while a mainframe is a large, powerful computer used mainly by large organizations for bulk data processing, such as census, industry and consumer statistics, enterprise resource planning, and financial transaction processing.