Life without computers
Nowadays, we cannot imagine our life without computers and the fact is that they have become so important that nothing can replace them. They seem to be everywhere today. Since 1948 when the first real computer has been invented our life has changed so much that we can call it real digital revolution.
First computers differed from today’s ones. They were so huge that they occupied whole rooms or buildings being relatively slow. They were not faster than modern simple watches or calculators. Nowadays they are also used by scientist and they may also be as huge as the old ones but they are millions times faster. They can perform many complex operations simultaneously and scientist practically can’t do without them. Thanks to them people has access to enormous amount of information. Gathering data has never been more simple than now. They are not only used in laboratories but also in factories to control production. Sometimes it is computers who manufacture other computers.
But not only in science and industry computers are being used. Thanks to them modern medicine can diagnose diseases faster and more thoroughly. Also in banking system computers have become irreplaceable. They control ATMs, all data is stored on special hard disks and paper isn’t used in accountancy any more. Furthermore, architects, designers and engineers can’t imagine their work without computers. This machines are really everywhere and we depend on them also in such fields as criminology. They help police to solve crimes and collect evidence.
Moreover, computers are wide-spread in education. Except their classic tasks such as administration and accountancy they are used in process of learning. Firstly, they store enormous amount of data which helps students to gain an information. Secondly, thanks to special teaching techniques and programs they improve ours skills of concentration and assimilation of knowledge. They have become so popular that not knowing how to use them means to be illiterate. Of course except this superb features there is also dark side of computer technology because every invention brigs us not only benefits but also threats.
Our PC (Personal Computer) is a system, consisting of many components. Some of those components, like Windows 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.
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. There’s another disk drive, called the hard disk inside the system unit. You can’t remove that disk, or even see it. But it’s there. And everything that’s currently “in your computer” is actually stored on that hard disk. (We know this because there is no place else inside the computer where you can store information). 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. Your computer’s hard disk can store as much information as tens of thousands of floppy disks, so don’t worry about running out of space on your hard disk any time soon. As a rule, you want to store everything you create or download on your hard disk. Use the floppy disks and CDs to send copies of files through the mail, or to make backup copies of important items.
- RANDOM ACCESS MEMORY (RAM)
There’s too much “stuff” on your computer’s hard disk to use it all at the same time. During the average session sitting at the computer, you’ll probably use only a small amount of all that’s available. The stuff you’re working with at any given moment is stored in random access memory (often abbreviated RAM, and often called simply “memory”). The advantage using RAM to store whatever you’re working on at the moment is that RAM is very fast. Much faster than any disk. For you, “fast” translates to less time waiting and more time being productive.
So if RAM is so fast, why not put everything in it? Why have a hard disk at all? The answer to that lies in the fact that RAM is volatile. As soon as the computer is shut off, whether intentionally or by an accidental power outage, every thing in RAM disappears, just as quickly as a light bulb goes out when the plug is pulled. So you don’t want to rely on RAM to hold everything. A disk, on the other hand, holds its information whether the power is on or off.
- THE HARD DISC
All of the information that’s “in your computer”, so to speak, is stored on your computer’s hard disk. You never see that actual hard disk because it’s sealed inside a special housing and needs to stay that way. Unlike RAM, which is volatile, the hard disk can hold information forever — with or without electricity. Most modern hard disks have tens of billions of bytes of storage space on them. Which, in English, means that you can create, save, and download files for months or years without using up all the storage space it provides.
In the unlikely event that you do manage to fill up your hard disk, Windows will start showing a little message on the screen that reads “You are running low on disk space” well in advance of any problems. In fact, if that message appears, it won’t until you’re down to about 800 MB of free space. And 800 MB of empty space is equal to about 600 blank floppy disks. That’s still plenty of room.
SCSI is a type of interface used for computer components such as hard drives, optical drives, scanners and tape drives . It is a competing technology to standard IDE (Integrated Drive Electronics). While the less expensive IDE technology is built into motherboards, SCSI is a technology that must be added by purchasing a SCSI controller. The SCSI card fits into an internal PCI slot. SCSI devices are then connected to this card. SCSI devices, particularly hard drives, are designed to be used 24/7 in addressing the needs of the server market. For this reason, SCSI drives are usually made to higher standards and carry longer warranties than IDE drives of comparable capacity. However, the added speed and quality come at a price. SCSI components are significantly more expensive than their IDE cousins.
- THE MOUSE
Obviously you know how to use your mouse, since you must have used it to get here. But let’s take a look at the facts and buzzwords anyway. Your mouse probably has at least two buttons on it. The button on the left is called the primary mouse button, the button on the right is called the secondary mouse button or just the right mouse button. I’ll just refer to them as the left and right mouse buttons. Many mice have a small wheel between the two mouse buttons.
- THE KEYBOARD
Like the mouse, the keyboard is a means of interacting with your computer. You really only need to use the keyboard when you’re typing text. Most of the keys on the keyboard are laid out like the keys on a typewriter. But there are some special keys like Esc (Escape), Ctrl (Control), and Alt (Alternate). There are also some keys across the top of the keyboard labeled F1, F2, F3, and so forth. Those are called the function keys, and the exact role they play depends on which program you happen to be using at the moment.
Most keyboards also have a numeric keypad with the keys laid out like the keys on a typical adding machine. If you’re accustomed to using an adding machine, you might want to use the numeric keypad, rather than the numbers across the top of the keyboard, to type numbers. It doesn’t really matter which keys you use. The numeric keypad is just there as a convenience to people who are accustomed to adding machines.
Most keyboards also contain a set of navigation keys. You can use the navigation keys to move around around through text on the screen. The navigation keys won’t move the mouse pointer. Only the mouse moves the mouse pointer.
On smaller keyboards where space is limited, such as on a notebook computer, the navigation keys and numeric keypad might be one in the same. There will be a Num Lock key on the keypad. When the Num Lock key is “on”, the numeric keypad keys type numbers. When the Num Lock key is “off”, the navigation keys come into play. The Num Lock key acts as a toggle. Which is to say, when you tap it, it switches to the opposite state. For example, if Num Lock is on, tapping that key turns it off. If Num Lock is off, tapping that key turns Num Lock on.
- INTERFACE CONTROLLERS
Interface controllers (parallel, serial, USB, Firewire) to connect the computer to external peripheral devices such as printers or scanners.
Graphics controller that produces the output for the monitor. The term computer graphics includes almost everything on computers that is not text or sound. Today almost every computer can do some graphics, and people have even come to expect to control their computer through icons and pictures rather than just by typing. Computer graphics as drawing pictures on computers, also called rendering. The pictures can be photographs, drawings, movies or simulations — pictures of things which do not yet exist and maybe could never exist. Or they may be pictures from places we cannot see directly, such as medical images from inside your body.
Software is a generic term for organized collections of computer data and instructions, often broken into two major categories: system software that provides the basic non-task-specific functions of the computer and application software which is used by users to accomplish specific tasks.
System software is responsible for controlling, integrating and managing the individual hardware components of a computer system so that other software and the users of the system see it as a functional unit without having to be concerned with the low-level details such as transferring data from memory to disk, or rendering text onto a display. Generally, system software consists of an operating system and some fundamental utilities such as disk formatters, file managers, display managers, text editors, user authentication (login) and management tools, and networking and device control software.
Application software, on the other hand, is used to accomplish specific tasks other than just running the computer system. Application software may consist of a single program, such as an image viewer; a small collection of programs (often called a software package) that work closely together to accomplish a task, such as a spreadsheet or text processing system; a larger collection (often called a software suite) of related but independent programs and packages that have a common user interface or shared data format, such as Microsoft Office, which consists of closely integrated word processor, spreadsheet, database, etc.; or a software system, such as a database management system, which is a collection of fundamental programs that may provide some service to a variety of other independent applications.
Software is created with programming languages and related utilities, which may come in several of the above forms: single programs like script interpreters, packages containing a compiler, linker, and other tools; and large suites (often called Integrated Development Environments) that include editors, debuggers, and other tools for multiple languages.Order Now