Let's begin by talking about the four necessary components of any information system. These are hardware, software, data, and procedures. Some sources also include two more components: people and feedback. Let's take a look at each of these.
Hardware is part of the necessary technology for any information system. It includes computers and their support elements (like keyboards, flash drives, etc.). Software is simply a computer program that tells the hardware what to do. Data refers to the facts we input into the software for the information system to store and process. Procedures are the guidelines that direct the input of data and the use of the software and hardware; they are basically the rules of the information system. Other sources identify the fourth component as a network that allows an information system to be shared.
People are, of course, necessary for any information system, since they are the ones doing the creating and the populating. Finally, feedback may indeed be necessary if the information system is to function as well as it possibly can.
Now let's think about why these components are so important. If we had no hardware, we could not build an information system at all. Computerized systems require computers, and they require computers that can handle the necessary software. The software itself is essential, for computers don't run without it. It must also be designed according to the type of information system being developed so that it is a good fit. Without data, there would simply be no need for an information system. Yet developers must make sure that the data they are collecting is both useful and secure. Finally, procedures are necessary to keep everyone on the same page so that the system can operate effectively.