TYPES AND

COMPONENTS OF

COMPUTER SYSTEM

Software: computer instructions or data. Anything that can be stored electronically is software, in contrast to storage devices and display devices which are called hardware.

Example: Operating Systems, Internet Browser, Games, Media player

HARDWARE: Hardware, in the computer world, refers to the physical components that make up a computer system.There are many different kinds of hardware that can be installed inside, and connected to the outside, of a computer.

Examples: CPU, RAM, Power Supply, Video card, Hard Drive, Monitor, Keyboard, Mouse.

Difference between Hardware and Software

Computer hardware is any physical device, something that you are able to touch and software is a collection of instructions and code installed into the computer and cannot be touched. For example, the computer monitor you are using to read this text on and the mouse you are using to navigate this web page is computer hardware. The Internet browser that allowed you to visit this page and the operating system that the browser is running on is considered software.

The Central Processing Unit (CPU) is responsible for interpreting and executing most of the commands from the computer's hardware and software.The CPU could be considered the "brains" of the computer. The CPU is Also Known Asprocessor, computer processor, microprocessor, central processor, "the brains of the computer"

RAM is the piece of memory where the programs and files you are using are stored, thus the files found in your RAM changes all the time (e.g MSN, Firefox, Word Docs, etc remains in RAM if you are using it). When your PC is switched off, data in your RAM is gone and cannot be recovered unless it has been saved on a permanent memory that is Hard Disk. 

ROM is the place where data that you cannot alter is stored, for example BIOS or Bootstrap Loader. ROM is used in the computer so that the processor does not have to look for important pieces of data when switched on, The processor just finds it in the ROM. You cannot edit files in ROM and data on it cannot be erased by turning off your PC

An input device is any hardware device that sends data to the computer, without any input devices, a computer would only be a display device and not allow users to interact with it. Example: Barcode, Keyboard, Scanner, Microphone.

An output device is any device used to send data from a computer to another device or user. Most computer data output that is meant for humans is in the form of audio or video. Thus, most output devices used by humans are in these categories. Examples include monitors, projectors, speakers, headphones and printers.

Alternatively referred to as external memory and auxiliary storage, secondary storage is a storage medium that holds information until it is deleted or overwritten regardless if the computer has power. For example, a floppy disk drive and hard drive are both good examples of secondary storage devices. 

OPERATING SYSTEMS

GUIShort for Graphical User Interface, the GUI  was first developed at Xerox PARC by Alan Kay, Douglas Engelbart, and a group of other researchers in 1981. Later Apple introduced the Lisa computer, the first commercially available computer on January 19, 1983. A GUI uses windows, icons, and menus to carry out commands such as opening files, deleting files, and moving files. Although many GUI Operating Systems are operated by using a mouse, the keyboard can also be utilized by using keyboard shortcuts or arrow keys.

CLIA CLI (command line interface) is a user interface to a computer's operating system or an application in which the user responds to a visual prompt by typing in a command on a specified line, receives a response back from the system, and then enters another command, and so forth.

A personal computer (PC) is a general-purpose computer, whose size, capabilities and original sale price makes it useful for individuals, and is intended to be operated directly by an end-user with no intervening computer operator.A desktop computer is a type of computer that fits on or under a desk, usually laying horizontally, compared to a tower that lays vertically. Unlike a laptop, a desktop computer is a stationary computer that remains at a desk. In the picture to right, is a picture of the Dell Precision 390 computer courtesy of Dell Inc. and an example of a Desktop PC.

Mainframe: A very large and expensive computers capable of supporting hundreds, or even thousands, of users simultaneously. In the hierarchy that starts with a simple microprocessor (in watches, for example) at the bottom and moves to supercomputers at the top, mainframes are just below supercomputers. 

Laptop :Alternatively referred to as a notebook, a laptop is aportable computer that with the same abilities as adesktop, but is small enough for easy mobility. Portable computers run off AC power or batteries, such as NiMH orNicad packs, for a few hours.

Palmtop: A small computer that literally fits in your palm. Compared to full-size computers, palmtops are severely limited, but they are practical for certain functions such as phone books and calendars. Palmtops that use a pen rather than a keyboard for input are often called hand-held computers or PDAs.

PDA: Short for personal digital assistant, a handheld device that combines computing, telephone/fax, Internet and networkingfeatures. A typical PDA can function as a cellular phone, fax sender, Web browser and personal organizer. PDAs may also be referred to as a palmtop, hand-held computer or pocket computer. Unlike portable computers, most PDAs began as pen-based, using a stylus rather than a keyboard for input.