Computer Science is really just the study of how a computer works. The main focus of Computer Science is to use the computer to solve a problem. Solutions to these problems can be solved using either hardware or software (but usually both).
The solutions to these problems can be for individuals, companies, or even the mass people of the world.
As stated above, some problems are software based (for example, how can we make a simple calculator? or how can we make a game?). Other problems are hardware based (for example, how can we build a faster computer?). And yet, other problems are both software and hardware based (for example, how can we connect computers together in a network?)
Please read the following pages to help you understand more about this topic.