The document discusses the key components of a computer system: hardware, software, data, and users. It describes the main hardware components as the central processing unit, memory (RAM and ROM), input/output devices, and storage devices. It explains that software tells the computer what to do and is divided into system software like operating systems and application software. It also defines computer data as facts without meaning on their own and that are stored using binary, and notes that users oversee the setup, maintenance and use of the computer system.