What is a computer?Edit
A computer is an automatic, electronic, data-processing machine that takes in facts and figures known as data, and then processes or organizes it in some useful way. Afterwards it outputs, or displays, the results for you to see as information. Keep in mind that data is not information. Rather, information is the knowledge that you, the end-user, derive from accurate data that are entered into a computer. Only after processing, is data transformed into information which is then used for decision making. There are two terms which must be correctly distinguished, hardware and software.
Hardware is all the parts of a computer that can be seen and touched. Hardware includes the internal components that we do not usually see unless we open up our machine. There are also external hardware devices which are outside the computer.
Many people mistakenly think that the part of the computer that normally displays pictures and text is the computer. This is usually not true. That part is called the monitor or display. With a standard desktop computer, the part that does the actual computing is often in a separate box. With a laptop or a netbook, the computing is done in the hardware under the keyboard. Also, you may call the whole assembly of all the hardware (the computer and the monitor, for example) the computer. Occasionally though, the computer and monitor are built together, in which case they are commonly referred to as All-in-One Desktop Computers.
There are different types of monitors. One of these is the one already shown. It is called a CRT monitor, which is similar to a old television. It uses more electrical power than the other popular kind, called LCDs . However, CRT monitors work faster, which makes them better for fast games because the movement will blur less , but LCD's have already caught up. LCDs are thinner than CRTs, but they are generally more expensive. As of now , CRT screens are no longer sold. Some monitorsuse touchscreens, where you can interace with the monitor by touch.
Monitors are only one way the computer can output information for you to see.
Printers and scannersEdit
Another popular output device is called a printer . Printers are used to put data on paper. This is called hard copy; what monitors show is called soft copy. There are different types of printers , like Xerox , laser and deskjet , with the last one being the cheapest of the three. There are also printers which can also scan/fax , they are called All-in-one.
Scanners are devices which scan the input for viewing on the computer.
There are also different kinds of input hardware. The two most important of which are the mouse and the keyboard. A mouse is used to move the cursor (or arrow) around the screen (monitor display). A keyboard is used to enter (type) letters, numbers, and other symbols into a computer.
Software is all of the instructions and programming that a computer uses to do what you ask it to do. Packages of software are often called programs, and an operating system is a collection of programs that help all the other programs run. Think of software as the power behind the hardware. Without software, your computer doesn't do anything. Without hardware, the software can't exist. Computers do not think for themselves, so they need software, which is made to manipulate the computer's hardware in such a way that you, the user, can understand.
As an example, a calculator is a very simple computer. It is not as complex or versatile as your net book, laptop, or desktop computer though. You input information as series of key presses, and the calculator computes the result which is displayed as output on a small screen. Since calculators are faster than humans this creates utility in the form of time saved. Calculators can also repeat calculations much more easily than humans can.
Computers store all data in binary code, which is a number system that only uses ones and zeros. One digit in binary code is called a bit, eight bits is called a byte. A byte is the amount of space one letter takes up. One thing to bear in mind is that all the extra detail about how the letter looks must also be stored in binary code and so word processor documents use more space than one byte per letter.
Types of computersEdit
There are many different kinds of computers. The ones that most people use are called Personal Computers (PCs). Desktop PCs are computers that you don't move around; they generally are a box with a monitor attached. Smaller, portable, computers that are about the size of a briefcase are called laptops or notebooks. There are also computers that are around the same size, but they have a special screen: Text (letters and numbers) is written directly on the screen, these are called Tablet PCs. They also do not require a mouse; the mouse gestures and clicks are done by tapping directly on the screen with your finger or with a Stylus. Personal Digital Assistants (PDAs) are computers so small that you can hold them in one hand. They generally also have a Touch Screen, like the Tablets. Notebooks, PDAs, and most Tablets have batteries so that you can use them without plugging into a wall outlet. These batteries generally last for about three to 8 hours , with some reaching 12 hours and beyond before needing to be recharged, although smaller devices may last longer. They use LCD screens because LCDs are thinner and take less power, so the batteries will last longer, and so that they are not, say, a foot thick. There are also much more powerful computers called servers that can be as big as a room or a house! This is what, say, Google and Wikimedia run their websites off of.
Turning the computer onEdit
In a desktop , to start the computer first make sure that the power supply is connected , and then press the switch which is usually on the front of the computer. On laptops and tablets , simply locate the power button and press it. If it comes up, and it is like this one, you must type the correct login name and password in the respective boxes. If you get a picture(Windows 8+) , then simply click it from the top. Then press the enter key, or click on (put the cursor on top of and push the left button on the mouse) the OK button if there is one. If the box does not come up, do not worry, nothing is wrong. That just means the computer is set not to have a password. We will learn more about this later. If this box did not come up, but instead a screen with pictures and names of the user accounts , click the picture with the correct user name beside it, type in the password (if there is one), and press(or tap) on your keyboard(or virtual) that says ‘Enter’.
Turning off the computerEdit
To turn the computer off,
|Windows version||What to do||Or||Or|
|Windows XP and below||Click Start , click Turn off Computer , and click Shut down.||(Classic)Click Start , click Shut down , and from the drop down, click Shut down and click OK.||On the desktop , hold down the ALT+F4 keys on the keyboard and follow the same instructions as given on the previous column.|
|Windows Vista||Click Start and click the power logo on the lower right.||Same as XP||Same as XP|
|Windows 7||Click Start and click Shut down on the lower right||Does not exist||Same as XP|
|Windows 8||Move the mouse to the right corner(or swipe from the right side) , move it up(or tap) , click Settings , click Power and click Shut down||Does not exist||Same as XP|
|Windows 8.1||Same as Windows 8||Right click on Start , move the mouse to Shut down or Sign out , and click Shut down||Same as XP|
There are some other methods not given here.
- Windows 8.1 with Update 1:-Press the Windows key on the keyboard , and click/tap the power icon on the upper-right corner of the Start screen , and click Shut down. If you do not have this feature , it is most likely because the tablet is 8 inches or less.
- All Windows versions:- This method is somewhat more advanced. Right click Command Prompt from the Accessories menu(in Windows 8+ , in All Apps)(or simply search) , click Run as Administrator and provide details if required(only for Windows Vista+ , for Windows XP and below , make sure that the account has administrator privileges.) , type shutdown.exe /s and press Enter. If you want to add a timer , just add /t x where x is the time in seconds. This timer can be up to 10 years in Windows 7+ or 10 minutes(600 seconds) in Windows Vista and below.