Its is a business sector that deals with computing, including hardware, software, telecommunications and generally anything involved in the transmittal of information or the systems that faciliate communication.
IT involves many things. Take, for instance, an IT department in a company. There are many people with many jobs and varied responsibilities. These responsibilities range from keeping systems and data secure to keeping networks up and running. There are people who input data, people who manage databases and people who do programming. There are also the decision makers, such as Chief Information Officers (CIOs), who decide how an IT department will operate and what components will be purchased.
IT also includes the management of data, whether it is in the form of text, voice, image, audio or some other form. It can also involve things related to the Internet. This gives IT a whole new meaning, since the Internet is its own realm. IT involves the transfer of data, so it makes sense that the Internet would be a part of IT. IT has become a part of our everyday lives and continues to proliferate into new realms.