What is Cookies

What is Cookies

A cookie is a small amount of data generated by a website and saved by your web browser. Its purpose is to remember information about you, similar to a preference file created by a software application.

While cookies serve many functions, their most common purpose is to store login information for a specific site. Some sites will save both your username and password in a cookie, while others will only save your username. Whenever you check a box that says, "Remember me on this computer," the website will generate a login cookie once you successfully log in. Each time you revisit the website, you may only need to enter your password or you might not need to log in at all.

Cookies are also used to store user preferences for a specific site. For example, a search engine may store your search settings in a cookie. A news website may use a cookie to save a custom text size you select for viewing news articles. Financial websites sometimes use cookies to store recently viewed stock quotes. If a website needs to store a lot of personal information, it may use a cookie to remember who you are, but will load the information from the web server. This method, called "server side" storage, is often used when you create an account on a website.

Browser cookies come in two different flavors: "session" and "persistent." Session cookies are temporary and are deleted when the browser is closed. These types of cookies are often used by e-commerce sites to store items placed in your shopping cart, and can serve many other purposes as well. Persistent cookies are designed to store data for an extended period of time. Each persistent cookie is created with an expiration date, which may be anywhere from a few days to several years in the future. Once the expiration date is reached, the cookie is automatically deleted. Persistent cookies are what allow websites to "remember you" for two weeks, one month, or any other amount of time.

Most web browsers save all cookies in a single file. This file is located in a different directory for each browser and is not meant to be opened manually. Fortunately, most browsers allow you to view your cookies in the browser preferences, typically within the "Privacy" or "Security" tab. Some browsers allow you to delete specific cookies or even prevent cookies from being created. While disallowing cookies in your browser may provide a higher level of privacy, it is not recommended since many websites require cookies to function properly.

OUTPUT DEVICES

OUTPUT DEVICES The devices which are used to display the data to the user either in the form of hard copy or soft copy are called output devices. SPEAKERS Speakers receive the sound in the form of electric current from the sound card & convert it to sound format. These are used for listening music, chatting , seminars for presentations etc.   VDU (Visual Display Unit) This is also called monitor. It is used to get the data in the form of soft copy. Their functioning is exactly similar to the television. It contains a CRT which emits the electrons to trace a regular pattern of horizontal lines on the screen. PRINTER These devices gives the hard copy of the output. These are in different types. Impact - Have mechanical contact in between paper & printing head Non Impact - No mechanical contact between paper & printing head DAISY PRINTER IMPACT : Line Printers - print line wise (E.g. Drum Printer) Character Printer - print character wise (E.g. Daisy Printer) NON IMPACT - Electromagnet Printers Thermal Printers Electrostatic Printers Inkjet Printers Laser Printers LCD (Liquid Crystal Display) These screens are used in laptops & notebook sized PCs. A special type of liquid is sandwiched between two plates. The top plate is clear & bottom plate is reflective. The molecules in these liquids are normally aligned & the computer signals are used to align these molecules. LED (Light Emitting Diodes)    A LED screen is a video display which uses light-emitting diodes. An LED panel is a small display, or a component of a larger display or screen

INPUT DEVICES

INPUT DEVICES

The input unit is formed by the input devices attached to the computer. Ex - Keyboard, Microphone etc. An input unit takes the input & converts it into binary form so that it can be understood by the computer. KEYBOARD This is most commonly used device which acts as input device. Its structure is like typewriter.It contains no. of  keys which have some specific ASCII values. Like ‘A’ has ASCII value 65. When this is pressed , it is converted into 65 & this 65 is sent to CPU in the form of Binary language (i.e. 1000001). Then operations are done on this data. MOUSE

This is a pointing device which contains a roller in its base. When the mouse is moved on any surface, the pointer on the screen is also moved. It contains a potentiometer coupled with the roller. This potentiometer senses the motion of mouse & convert it into digital value. A mouse may contain two or three buttons. Now a day's optical mouse are very popular.

BAR CODE READER

It is a device which is used to read the code from the products which are usually in the form of Bars. It contains a light sensitive detector which identifies the values of the bars on the product & converts them into numeric code. These Bar readers are used in Shopping malls in a very large scale.

DIGITAL CAMERA

As the name specifies, these camera stores the data digitally, which then can be stored in the computer & can be stored for a long time. But it has very limited storage capacity. These are very popular because of less expensive photographs & Speed.

LIGHT PEN

It is a pointing device which contains a photocell mounted at its tip. It senses the light from the screen when it becomes closer to the screen, & generates a pulse. So for identifying a particular location on the screen these light pens are very useful. But this is not in very much use these days.

SCANNER

The scanner is an input device like the photocopier machine which makes the electronic copy of the picture or document which can be further edited.

MIC's or MICROPHONES

The scanner is an input device like the photocopier machine which makes the electronic copy of the picture or document which can be further edited. 

CPU Central Processing Unit The CPU is the control center for a computer. It guides, directs & governs its performance. It is the brain of the computer. CPU CONTAINS : 1. Arithmetic & Logical Unit 2. Control Unit ARITHMETIC & LOGICAL UNIT An Arithmetic and Logical Unit (ALU) is a digital circuit  that performs arithmetic and logical operations. The ALU is a fundamental building block of the central processing unit (CPU) of a computer. ALU is a combination of Arithmetic Unit & Logical Unit. ARITHMETIC UNIT Arithmetic Unit performs all the arithmetic operations like addition , subtraction , multiplication & division performed on the operands. For example : a + b a - b a * B a / b CONTROL UNIT Control Unit is most important part which controls all the internal as well as external functions in the computer. THE MAIN FUNCTIONS PERFORMED BY THE CONTROL UNIT ARE : 1. It controls & guides the interpretation , flow    & manipulation of all data & information. 2. It sends control signals until the required operations are done properly by ALU & memory. 3. It gets program instructions from memory & executes them one after another. 4. It controls the flow of data from input device to memory & from memory to output devices.			CPU HARDWARE

GENERATIONS OF COMPUTER FIRST GENERATION

FEATURES OF FIRST GENERATION

1. Use of vacuum tubes

2. Big & Clumsy

3. High Electricity Consumption

4. Programming in Mechanical Language

5. Larger AC were needed

6. Lot of electricity failure occured

SECOND GENERATION

FEATURES OF SECOND GENERATION

1. Transistors were used

2. Core Memory was developed

3. Faster than First Generation computers

4. First Operating System was developed

5. Programming was in Machine Language & Assembly Language

6. Magnetic tapes & discs were used

7. Computers became smaller in size than the First Generation computers

8. Computers consumed less heat & consumed less electricity

THIRD GENERATION

THIRD GENERATION FEATURES

1. Integrated circuits developed

2. Power consumption was low

3. SSI & MSI Technology was used

4. High level languages were used

FOURTH GENERATION

FOURTH GENERATION COMPUTERS

1. LSI & VLSI Technology used

2. Development of Portable Computers

3. RAID Technology of data storage

4. Used in virtual reality, multimedia, simulation

5. Computers started in use for Data Communication

6. Different types of memories with very high accessing speed & storage capacity

FIFTH GENERATION

 FIFTH GENERATION COMPUTERS

1. Used in parallel processing

2. Used superconductors

3. Used in speech recognition

4. Used in intelligent robots

5. Used in artificial intelligence

        

Top 10 Windows 8 tips and tricks

Customize your tiles

Make the most of your Windows Start screen tiles by adjusting the sizes, where they are located, and what is listed.

• Move any tile by clicking and dragging the tile. While moving a tile, if you need a larger view of the Start screen move the tile towards the top or bottom of the screen to zoom out.
• Use your mouse wheel to scroll left-to-right through your tiles.
• Any Desktop shortcut or program can be pinned to the Start screen by right-clicking the icon and choosing Pin to Start.
• In the bottom right-hand corner of the start screen is a magnifying glass with tiles, click this icon to get a zoomed out view of your Start screen. In this view, if you right-click on a group of tiles you'll be given the option to name group, which can be useful if you have a group of related tiles (e.g. games). In this view, you can also click and drag a group to organize your tile groups.
• Create a new speed bump between tile groups by moving a tile to a speed bump.
• Resize any User tile or Live tile by right-clicking the tile and choosing resize.
• If there is a tile you want on your Taskbar, right-click the tile and choose Pin to taskbar.
• Show admin applications on the Start screen by clicking Settings in Charms, click Settings, and change the Show administrative tools from No to Yes.
• In Internet Explorer 10, you can also pin any of your favorite web pages to your Start Screen

Top 10 keyboard shortcuts everyone should know

Using keyboard shortcuts can greatly increase your productivity, reduce repetitive strain, and help keep you focused. For example, highlighting text with the keyboard and pressing Ctrl + C is much faster than taking your hand from the keyboard, highlighting the text using the mouse, clicking copy from the file menu, and then putting your hand back in place on the keyboard. Below are our top 10 keyboard shortcuts we recommend everyone memorize and use.

Ctrl + C or Ctrl + Insert

Copy the highlighted text or selected item.

Ctrl + V or Shift + Insert

Paste the text or object that's in the clipboard.

Ctrl + Z and Ctrl + Y

Undo any change. For example, if you cut text, pressing this will undo it. This can also often be pressed multiple times to undo multiple changes. Pressing Ctrl + Y would redo the undo.

Ctrl + F

Open the Find in any program. This includes your Internet browser to find text on the current page.

Alt + Tab or Alt + Esc

Quickly switch between open programs moving forward.

Tip: Press Ctrl + Tab to switch between tabs in a program.

Tip: Adding the Shift key to Alt + Tab or Ctrl + Tab will move backwards. For example, if you are pressing Alt + Tab and pass the program you want to switch to, press Alt + Shift + Tab to move backwards to that program.

Tip: Windows Vista and 7 users can also press the Windows Key + Tab to switch through open programs in a full screenshot of the Window.

Ctrl + Back space and Ctrl + Left or Right arrow

Pressing Ctrl + Backspace will delete a full word at a time instead of a single character.

Holding down the Ctrl key while pressing the left or right arrow will move the cursor one word at a time instead of one character at a time. If you wanted to highlight one word at a time you can hold down Ctrl + Shift and then press the left or right arrow key to move one word at a time in that direction while highlighting each word.

Ctrl + S

While working on a document or other file in almost every program pressing Ctrl + S will save that file. This shortcut key should be used frequently anytime you're working on anything important.

Ctrl + Home or Ctrl + End

Move the cursor to the beginning or end of a document.

Ctrl + P

Print the page being viewed. For example, the document in Microsoft Word or the web page in your Internet browser.

Page Up, Space bar, and Page Down

Pressing either the page up or page down key will move that page one page at a time in that direction. When browsing the Internet pressing the space bar will also move the page down one page at a time. If you press Shift and the Space bar the page will go up a page at a time