Computer Tutorials, Tips and Tricks

Friday, 30 December 2011

Basics of Internet

Introduction to Internet
The Internet is a worldwide collection of interconnected computer networks that enables businesses, organizations, governments, and individuals to communicate in a variety of ways. One of the most popular ways users communicate on the Internet is by publishing and interacting with Web pages. You can also use the Internet to send and receive e-mail, chat with other users, and transfer files between computers.

Internet Explorer

Types of Connections

Users connect to the Internet through a variety of methods. A relatively inexpensive but slow way to connect is with dialup service, which involves using a modem and a phone line. Faster ways to connect include DSL (digital subscriber line), cable modem, satellite, and ISDN (integrated services digital network). Networks include special wireless transmitters that allow computers to access the Internet wirelessly. Companies that help you connect to the Internet are known as Internet service providers, or ISPs.

Connection Speeds
Connection speeds play an important part in a user’s Internet experience because slower connections result in slower file transfers and Web page viewing. Dialup connections offer the slowest access to the Internet at up to 56 kilobits per second, or Kbps, followed by ISDN connections at 64 to 128 Kbps. DSL usually offers connection speeds of up to 3 megabits per second, or Mbps, while cable modems can achieve speeds of up to 6 Mbps. A Web page that takes about 20 seconds to download via dialup can take less than a second using a cable modem.

Communication Standards
The Internet infrastructure relies on a variety of protocols that dictate how computers and networks talk to each other. For example, Transmission Control Protocol/Internet Protocol, or TCP/IP, is a set of rules that control how Internet messages flow between computers. Hyper Text Transfer Protocol, or HTTP, is a set of rules that determine how browsers should request Web pages and how server computers should deliver them. Having agreed-upon protocols allows seamless communication among the many different types of computers that connect to the Internet.

The World Wide Web
The World Wide Web is a giant collection of documents, or pages, stored on computers around the globe. Commonly called the Web, this collection of pages represents a wealth of text, images, audio, and video available to anyone with a computer and an Internet connection. Web pages are stored on servers, which are Internet-connected computers running software that allows them to serve up information to other computers. When you place a text file, image, or other document in a special Web directory on a server, that information is available for other Web users to view.

URLs and Links
Every page on the Web has a unique address called a URL, which is short for Uniform Resource Locator. A URL looks like this: http://www.example.com/index.html. If you know a page’s URL, you can type it into a Web browser to view that page over the Internet. You can also view pages by way of hyperlinks, or simply links, which are click-able words or images on Web pages. Every link on a Web page is associated with a URL that leads to another page on the Internet. Users can jump from one Web page to another by clicking links.

Browsers
A Web browser is software that allows you to view and interact with Web pages. When you type a URL or click a link in a Web browser, the browser retrieves the appropriate page from a server on the Internet and displays that page. Microsoft Internet Explorer, Mozilla Firefox, and Apple Safari are the three most popular browsers in use today. Each program has evolved through a number of versions, with newer versions supporting more recent Web features. As you build your pages using HTML code, remember that different browsers may display your pages slightly differently depending on the version.

Thursday, 29 December 2011

WHAT PIECES ARE FOUND IN A COMPUTER?

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Monitor	The CRT or display that shows the words, graphics, etc., to the user. It is a critical part of a user’s interface.
Motherboard	A printed circuit board that has (at least) slots to connect cards into. Often, they also include a CPU and memory.
Mouse	An input device which has one to three buttons and when you move it, it causes the arrow in a Windows display to move.
Printer	An external device that takes commands and data from the computer to place on paper. There are several types of printers: daisy-wheel, matrix, laser, thermal, inkjet, and plotter.
RAM	“Random Access Memory“. A pool of storage for the CPU. It can be written to/read from in any order (unlike a VCR tape which is serial— you have to wind to the place you want). There are several types of RAM: SRAM, DRAM, EDO-RAM.
ROM	“Read Only Memory“. Memory that has imprinted in it data and programs for the CPU which cannot be erased or written to.
Scanner	An external device that is able to optically read in printed material—kind of like a copier, but it stores the image on the computer instead.
UPS	“Uninterruptable Power Supply”. This is a box that is like a surge protector but will keep you going even if you lose power. You can plug your computer into. If you have a brown- or black-out, this unit will keep you running for 3 minutes to an hour (certainly enough time to save your work and shutdown the computer).
CD-ROM	A disk made of plastic and aluminum which can store up to 650MB of data. Usually these disks cannot be written to, instead they often are used to distribute software from companies.
CPU	Central Processing Unit. The “brain” of the computer. It executes commands which, eventually, we see as a response to our input. Without the CPU, the computer is nothing.
Hard disk	A medium to store data for the computer while the power is out. It uses a hard material (typically aluminum).
Keyboard	A typewriter-like tool that has keys. Sends letters or commands to the computer.
Microprocessor	A CPU that composes only one chip. Some CPUs may actually be several square feet is size; but, the microprocessor is designed to be 100% self-contained in a single chip.
Modem	A device that will let your computer talk to other computers through the telephone line.
DVD	The next generation CD-ROM which will store 10-20x the current capacity.
Card Slot	The slots found on the PC motherboard may be one of five types: ISA EISA, MCA, VESA & PCI.. Slower adapters (like I/O boards) can be ISA. But for the best performance, use VESA or PCI for hard drives, CD-ROMs or Video adapters.
Cable Cache	A thick wire that connects the computer to the external device or power. An interface between the CPU and the memory (RAM and ROM). It helps the CPU keep running even though the RAM may be too slow. It does this by keeping a copy of what the processor has read/written.
Adapter	Most of the time it refers to a card that plugs into the motherboard adding special capabilities not originally found on the computer. Other times it refers to tools to convert one connector type to another.

Tuesday, 27 December 2011

What are Output Devices Of Computer?

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Output Devices: Output Devices of computer are those devices which are used to communicate the computer for displaying process data to the user which is operating the computer. These days many devices are used as output devices of a computer. Most of the computer users only aware of Monitor and Printer as output devices of computer. There are also other output devices which we are using as output devices of a computer. Below are the list of computer output devices.

Output Devices Of Computer

An output device is any piece of computer hardware equipment used to communicate the results of data processing carried out by an information processing system (such as a computer) to the outside world.

In computing, input/output, or I/O, refers to the communication between an information processing system (such as a computer), and the outside world. Inputs are the signals or data sent to the system, and outputs are the signals or data sent by the system to the outside.

Examples of output devices:

Headphone - Output Device

Speakers
Headphones
Screen (Monitor)
Printer

Some more images of Output Devices :

Monitor - Output Device

Printer - Output Device

Speakers - Output Device

What Are Input Devices Of Computer?

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In the world of computing, input devices are any peripheral (piece of computer hardware equipment) used to provide data and control signals to an information processing system such as a computer or other information appliance. Input and output devices make up the hardware interface between a computer and a scanner. Normally, Input devices of computers are used to give instructions to the computer and output has to be processed through processing devices to output devices. Keyboard and mouse are two famous input devices of a computer which is used in every computer. These days we are also using some latest input devices like Light Pen, Trackball Mouse, and pen drives. Below are some images of input devices of computer:

Keyboard - Input Device

Mouse - Input Device

Scanner - Input Device

Input Devices - Keyboard And Mouse

USB/Pen Drive - Input Device

Many input devices can be classified according to:

modality of input (e.g. mechanical motion, audio, visual, etc.)
the input is discrete (e.g. key presses) or continuous (e.g. a mouse's position, though digitized into a discrete quantity, is fast enough to be considered continuous)
the number of degrees of freedom involved (e.g. two-dimensional traditional mice, or three-dimensional navigators designed for CAD applications)

Pointing devices, which are input devices used to specify a position in space, can further be classified according to:

Whether the input is direct or indirect. With direct input, the input space coincides with the display space, i.e. pointing is done in the space where visual feedback or the pointer appears. Touchscreens and light pens involve direct input. Examples involving indirect input include the mouse and trackball.
Whether the positional information is absolute (e.g. on a touch screen) or relative (e.g. with a mouse that can be lifted and repositioned)

Mouse - Input Device

Direct input is almost necessarily absolute, but indirect input may be either absolute or relative. For example, digitizing graphics tablets that do not have an embedded screen involve indirect input and sense absolute positions and are often run in an absolute input mode, but they may also be set up to simulate a relative input mode where the stylus or puck can be lifted and repositioned.

Read detailed article about Input Devices here : http://www.indiastudychannel.com/resources/115991-INPUT-DEVICES.aspx

Sunday, 25 December 2011

What is HTML?

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HTML is a language for describing web pages.

HTML stands for Hyper Text Markup Language
HTML is not a programming language, it is a markup language
A markup language is a set of markup tags
HTML uses markup tags to describe web pages

HTML Tags

HTML markup tags are usually called HTML tags

HTML tags are keywords surrounded by angle brackets like <html>

HTML tags normally come in pairs like <b> and </b>

The first tag in a pair is the start tag, the second tag is the end tag

Start and end tags are also called opening tags and closing tags

HTML Documents = Web Pages

HTML documents describe web pages

HTML documents contain HTML tags and plain text

HTML documents are also called web pages

Know more about HTML Tags : http://www.indiastudychannel.com/resources/145204-How-use-HTML-tags.aspx

What is SQL DML and DDL?

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SQL can be divided into two parts: The Data Manipulation Language (DML) and the Data Definition Language (DDL).

The query and update commands form the DML part of SQL:

SELECT - extracts data from a database
UPDATE - updates data in a database
DELETE - deletes data from a database
INSERT INTO - inserts new data into a database

The DDL part of SQL permits database tables to be created or deleted. It also defines indexes (keys), specify links between tables, and impose constraints between tables. The most important DDL statements in SQL are:

CREATE DATABASE - creates a new database
ALTER DATABASE - modifies a database
CREATE TABLE - creates a new table
ALTER TABLE - modifies a table
DROP TABLE - deletes a table
CREATE INDEX - creates an index (search key)
DROP INDEX - deletes an index

What is SQL?

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SQL stands for Structured Query Language
SQL lets you access and manipulate databases
SQL is an ANSI (American National Standards Institute) standard

What Can SQL do?

SQL can execute queries against a database
SQL can retrieve data from a database
SQL can insert records in a database
SQL can update records in a database
SQL can delete records from a database
SQL can create new databases
SQL can create new tables in a database
SQL can create stored procedures in a database
SQL can create views in a database
SQL can set permissions on tables, procedures, and views

Sunday, 6 November 2011

Microsoft Office 2010

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Despite it being the second most used application on my work computer (behind the Mozilla Firefox browser),it’s still impossible for me to get excited about a new edition of the Microsoft Office suite.
With the final release due in a couple of months,Microsoft have provided a beta test version of Office 2010 that’s free for members of the public to download. The beta test version will run unhindered until October 2010 at which point users must decide whether they wish to purchase the final release or have it removed from their hard drive.
For the costs involved the majority of home users may still be better off with the free OpenOffice Suite (www.openoffice.org) as it should provide all the features you are likely to need at no cost. This having been said,the Office Suite has remained a popular flagship product over the years due to business users often requiring a specific function or application only present in the Microsoft offering. I,for example,use Outlook on a regular basis and haven’t yet found an alternative that suits my needs.
Having not been the biggest fan of Office 2007 (especially the ‘ribbon’ interface discussed in the past) I wasted no time downloading the 64-bit professional version of the beta to put it through its paces. I have now been using it for a couple of days it does appear notably faster than Office 2007 and certainty incredibly stable. The speed increase could easily be attributed to the fact that a 64-bit version of the application is now available to run on modern 64-bit computers.
Office Professional 2010 includes Word,Excel,PowerPoint,InfoPath,OneNote,Outlook,Access and Publisher. The home edition (also currently available in beta) includes Word,Excel,PowerPoint,Outlook and OneNote. After the official release,computer manufacturers may choose to bundle new machines with a starter edition of Office which includes just Excel and Word;this version of Office will replace the aging Microsoft Works Suite.
Although the ribbon interface remains,it is certainly a lot clearer than that provided with Office 2007;the confusing Office orb has been replaced with the familiar file menu,there are fewer distracting borders,a neutral colour scheme and most importantly it is customisable to the users individual tastes. The applications look and behave like a ‘family’ now and have become more intuitive to use as a result of the more refined user interface.
An important new feature due for release in the final version but missing from the beta is the ‘Web Apps’ which will extend the Office functionality to a compatible web browser. Very similar in form to Google Docs,Office Web Apps allows users to collaborate,edit and share Office documents online. This is an incredibly important new feature that has no doubt come about due to the success of Google Docs and one that I would like to field test when complete.
This article isn’t long enough to go in to details about minor new features so I will summarise by observing that the changes made from Office 2007 to Office 2010 are evolutionary rather than revolutionary;very much in the same way that Windows 7 was an evolutionary change compared with Vista. Excluding the Web Apps there is nothing substantially new however the minor improvements are certainly welcome as is the chance to road test a new piece of software completely free of charge for a year.
Users interested in downloading the beta version of Office 2010 should visit www.microsoft.com/office/2010 to get their hands on a copy.

Reference : http://www.computerarticles.co.uk

Windows 7 Hidden Gems –Additional functionality

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I’ve been living with Windows 7 for a good few months now and in that time have discovered a couple of little ‘hidden gems’ which I wanted to share with you:
Aero Shake
In Windows 7,when you click on the title bar of any window and shake it every other open window gets minimized straight back in to your task bar,reducing clutter on your screen. This allows you to focus on the one window and then when ready shake it again and the other windows will reappear.
There are additional Aero user interface related features which make a welcome debut. These include Aero Peek which allows you to immediately see what’s going on in an application just by hovering over the icon in the task bar and Aero Snap which quickly allows you to rearrange your desktop by slamming any open window against the left,right or top side of your screen;try it!
Sticky Notes
Proof,if needed,that some of the simplest applications make the largest differences to the end user experience. One of the most commonly used applications on my PC used to be the incredibly simple ‘notepad’ as I find that my working life works a lot better if I simplify everything down in to lists.
Rather than jotting notes on random pieces of paper that will almost certainly get lost throughout the day I used to dump everything in notepad and ensure that every line was eventually cleared so I was left with a blank page before I went home.
Sticky notes have a similar application. To get started click on the start menu and type in ‘sticky’ and begin typing tasks for the day or things to remember in to little post it notes that stick to your screen. When complete either close or minimize the application to get back to the job in hand,safe in the knowledge that once Sticky Notes are reopened,these tasks will reappear exactly as you left them. When a task has been completed or the note simply isn’t needed,it can be deleted with one click of the mouse.
Improved Calculator
Windows 7 calculator has improved considerably;now rather than being an arithmetic only affair,it can be operated in four modes –Standard,Scientific,Programmer and Statistical. It can also perform unit conversion,for example grams to ounces,metres to feet and Celsius to Fahrenheit along with a couple of unexpected features such as the ability to calculate the number of days between two dates or the value of your mortgage repayment. Surely in the next version of Windows the calculator application will finally gain graphical capabilities.
Windows Disk Image Burner
For some time now the preferred method of copying and storing CD’s and DVD’s has been by using an ISO file;a single image which includes the contents of an entire disk. Reading these files used to require a specific application (the likes of which I’ve covered previously in Click) but every version of Windows 7 now includes support for these straight out the box;simply double click on the ISO file that you wish to burn,insert a blank CD or DVD and you’re done.

Reference : http://www.computerarticles.co.uk