1.2 Computer Systems

A computer system is made up of a hardware and a software components. The physical machine that you see is the hardware of the computer system. This physical machine needs a “brain” to make it work, and that is the software component. Let us take a closer look at these two components.

2.1 Hardware

A computer system basically has 5 components: input device, output device, the processor (or better known as CPU), main memory (better known as RAM), and secondary memory.

An input device is to allow a person to communicate information to the computer. In can be a keyboard, a mouse, a touch screen or any other device that allows a person to enter an input or response to the computer.

An output device allows the computer to communicate information to the human, such as displaying information on a display monitor, printing out information on a printer, producing information as a sound from a speaker, ect.

The computer’s processor and the main memory form the heart of the computer and are usually thought of a one integrated unit.

The secondary memory is used to store a permanent copy of the information. A hard disk is the most common type of secondary memory you will see. Other secondary memory are tapes, disks (CD or DVD), thumb drives, etc.

1.2 Computer Systems

2.2 Software

A software is the program that allows you to “talk” to the computer. First of all, the computer must have a program which is called the operating system. The operating system is a special program which was written by experts and its main purpose is to allow the machine to interact with you. The operating system controls the computer’s resources. If you want to run a program, you will tell the operating system the name of the file that contains it, and the operating system will run the program. This program which you want to run is called an application program. Application programs can be programs which you buy, or it can be programs which you write yourself.

A program is a set of instructions for a computer to follow. It can be a simple set of instructions, or a complex one. In this course you will learn how to design and write programs. Programs can be written using computer languages. In this course we will use the C++ language to practice our program writing.