Your PC (Personal Computer) is a system, consisting of many components. Some of those components, like Windows XP, and all your other programs, are software. The stuff you can actually see and touch, and would likely break if you threw it out a fifth-story window, is hardware.

                                                                    Figure 1

The system unit is the actual computer; everything else is called a peripheral device. Your computer's system unit probably has at least one floppy disk drive, and one CD or DVD drive, into which you can insert floppy disks and CDs.

Figure 2

The floppy drive and CD drive are often referred to as drives with removable media or removable drives for short, because you can remove whatever disk is currently in the drive, and replace it with another.