Terminology

**Computer Terminology**
Storage space definitions: A bit is the smallest unit of data, a single on or off switch, a zero or a one. A byte is eight bits and can represent one of 256 characters - letters, numbers, punctuation, etc. A kilobyte, often abbreviated K or KB, is 1,024 bytes, roughly a page of text. A megabyte, often abbreviated M or MB, is 1,024 kilobytes. A gigabyte, often abbreviated G or GB, is 1,024 megabytes. A terabyte is 1,024 gigabytes; a petabyte is 1,024 terabytes. So far, gigabytes seem to be the maximum home users need to know.

Software and Hardware: Hardware refers to the physical parts of the computer. If you can touch it, install it, etc., then it’s hardware. Software refers to the programming instructions, data files, and any other collection of information stored on one of the storage devices. The main piece of software is the Operating System, which is the primary program the computer is running, which provides the environment where all the other programs run. In our case, the operating system is Windows XP. If the operating system isn’t running first, you can’t run other programs. The term “booting the computer” refers to starting the computer and loading the operating system; the word “boot” is taken from the phrase “pulling yourself up by your bootstraps”.

Inside the computer: Motherboard: The primary circuit board of a computer, where everything else plugs in to. CPU: The Central Processing Unit is the main brain of your computer, the chip where most of the work gets done. Chip speed is measured in hertz - nowadays mostly megahertz and gigahertz - and the bigger this number, the faster your computer, although of course other elements factor into overall speed as well. Newer computers feature more than one processor, and the latest fit two processors onto one chip - these are called “dual core” processors.

RAM (“Random Access Memory”, or simply “memory”): The chips where temporary information is stored. When the computer shuts down, this memory is erased. HD (Hard Disk): The device that stores data which is saved when the computer is shut down. The operating system, programs, and files reside here. Removable media: Depending on what type of disk drive you have, you will be able to read and write CDs and DVDs. A CD can store up to 700 megabytes, and a single-layer DVD can fit 4.4 gigabytes. It is also possible you may encounter the older 3.5” “floppy” discs, which store very little (by today’s standards), around one megabyte. A better alternative to floppies are USB flash memory sticks - unlike RAM, flash memory does not erase itself when the power goes out, and these tiny sticks of memory can be much faster than floppies.

Cards: Various functions can be added or enhanced by the use of cards which plug into the motherboard. For example, most computers nowadays use a video card to run the monitor, which frees the CPU from that task.

Outside the computer: Keyboard: the device you type with. Monitor: the screen you look at.

Mouse: the device you move across the table Trackball: a similar device which stays still and uses a rolling ball.

USB ports: In the beginning, there was no single way to plug things into the computer, and whenever something had to be plugged in, you had to shut the computer off. USB stands for Universal Serial Bus, and not only did it standardize the plug for most (but not all) external devices you’ll need to plug into your computer, it also allows things to be plugged in and removed while the computer is on. If you need more USB ports than your computer has, you can buy a “hub” which splits one USB port into severa. You can plug hubs into other hubs and connect up to a maximum of 127 devices. USB ports can be recognized by this symbol: * Reference: http://en.wikipedia.org/wiki/Computer_hardware