Lecture#01 (Introduction to Computer)

I like my new mobile, my computer works just fine, my calculator is perfect, but Lord, I miss my mind!  ~Majid Yaseen

Dears Assalam-o-alaikum!

              We hope that you people will be all right and will be committed to have the pleasure of Almighty Allah. 
In the previous post we promised you people to come back with weekly lectures and now we are here with what we have promised . . . .


So our first lecture is about Computers.

First Lecture

Computers

Whether you are new to the computer, returning for review or just want to gain more 21st century skills, we are here to deliver. . . . .

Computer Basics

Are you new to using computers? Do you wonder what people mean when they say the Cloud, Windows, Blackberry, Lion, etc.? Perhaps you would just like to know more about how computers work? When it comes to learning today's technology, Computer Basics has all the basic concepts covered.

Getting to Know Computers

What is a Computer?

A computer is an electronic device that manipulates information, or "data." It has the ability to store, retrieve, and process data. You can use a computer to type documents, send email, and browse the internet. You can also use it to handle spreadsheets, accounting, database management, presentations, games, and more.

Computers Simplified

For beginning computer users, the computer aisles at an electronics store can be quite a mystery, not to mention overwhelming. However, computers really aren't that mysterious. All types of computers consist of two basic parts:

• Hardware is any part of your computer that has a physical structure, such as the computer monitor or keyboard.
• Software is any set of instructions that tells the hardware what to do. It is what guides the hardware and tells it how to accomplish each task. Some examples of software are web browsers, games, and word processors such as Microsoft Word.

                       Anything you buy for your computer can be classified as either hardware or software. Once you learn more about these items, computers are actually very straightforward.

v The first electronic computer, the Electronic Numerical Integrator and Computer (ENIAC), was developed in 1946. It took up 1,800 square feet and weighed 30 tons.

What are the Different Types of Computers?

When most people hear the word "computer" they think of a personal computer such as a desktop or laptopcomputer. However, computers come in many shapes and sizes, and they perform many different functions in our daily lives. When you withdraw cash from an ATM, scan groceries at the store, or use a calculator, you're using a type of computer.

Desktop Computers

Many people use desktop computers at work, home, school, or the library. They can be small, medium, or large in style, and usually sit on a desk. Once you add a monitor, mouse, and a keyboard, you have what is typically known as a desktop computer.

Most desktop computers are easy to upgrade and expand, or add new parts. Another benefit of desktop computers is the cost. If you compare a desktop and a laptop with the same features, you will most likely find that the desktop computer is priced lower.

Some desktop computers have a built-in monitor to save space. These are often called all-in-one desktop computers.

Laptop Computers

The second type of computer that you may be familiar with is a laptop computer or laptops as they are often referred to. Laptops are battery or AC-powered personal computers that are more portable than desktop computers, allowing you to use them almost anywhere.

Since a laptop is smaller than a desktop, it's more difficult to access the internal components. That means you may not be able to upgrade them as much as a desktop. However, it's usually possible to add more RAM or a bigger hard drive.

v A laptop computer is sometimes called a notebook computer because of its size.

Servers

A server is a computer that "serves up" information to other computers on a network. Many businesses have file servers that employees can use to store and share files. A server can look like a regular desktop computer, or it can be much larger.

Mac OS is a line of operating systems created by Apple Inc. It comes preloaded on all new Macintosh computers, or Macs. All of the recent versions are known as Mac OS X (pronounced Mac O-S Ten), and their specific version names are Lion (released in 2011), Snow Leopard (2009) and Leopard (2007). Apple also offers a version called Mac OS X Server, which is designed to be run on servers.

According to Stat Counter Global Stats , Mac OS X users account for 6.3% of the operating systems market as of June 2011 - much lower than the percentage of Windows users (over 90%). One reason for this is that Apple computers tend to be more expensive. However, many people prefer the look and feel of Mac OS X.

Linux

Linux (pronounce LINN-ux) is a family of open source operating systems, which means that they can be modified and distributed by anyone around the world. This is very different from proprietary software like Windows, which can only be modified by the company that owns it (Microsoft). The advantages of Linux are that it is free, and there are many different distributions (or versions) that you can choose from. Each distribution has a different look and feel, and the most popular ones include Ubuntu, Mint, and Fedora.

Linux is named after Linus Torvalds, who created the Linux kernel in 1991. The kernel is the computer code that is the central part of an operating system.

According to Stat Counter Global Stats , Linux users account for less than 1% of the operating systems market as of June 2011. However, most servers run Linux because it's relatively easy to customize.

Operating Systems for Mobile Devices

The operating systems that we've been talking about were designed to run on desktop or laptop computers. Mobile devices such as phones, tablet computers, and mp3 players are very different from desktop and laptop computers, so they run operating systems that are designed specifically for mobile devices. Examples of mobile operating systems include Apple iOS, Windows Phone 7, and Google Android.

Operating Systems for mobile devices generally aren't as fully-featured as those made for desktop or laptop computers, and they aren't able to run all of the same software. However, you can still do a lot of things with them, such as watching movies, browsing the internet, managing your calendar, playing games, and more.

You may have heard people talking about using an application or an app. But what exactly does that mean? An application (or app) is a type of software that allows you to perform specific tasks. Applications for desktop or laptop computers are sometimes called desktop applications, and those for mobile devices are called mobile apps. When you open an application, it runs inside the operating system until you close it. Much of the time, you will have more than one application open at the same time, and this is known as multitasking.

App is a very common slang term for an application, especially for simple applications that can be downloaded cheaply or even for free. Many apps are also available for mobile devices and even some TVs.

Types of Desktop Applications

There are countless desktop applications out there, and they fall into many different categories. Some are more full-featured (like Microsoft Word), while others may only do one or two things (like gadgets). Below are just a few types of applications that you might use:

• Word Processors: A word processor allows you to write a letter, design a flyer, and create many other kinds of documents. The most well-known word processor is Microsoft Word.

• Personal Finance: Personal finance software, such as Quicken, allows you to keep track of your income and expenses, create a budget, and more. Most personal finance programs can automatically download information from your bank, so you don't have to manually type in all of your transactions
• Web Browsers: A web browser is the tool that you use to access the World Wide Web. Most computers come with a web browser pre-installed, but you can also download a different one if you prefer. Examples of browsers include Internet Explorer, Firefox, Google Chrome, and Safari.

Games: There are many different games that you can play on your computer. They range from card games such as Solitaire, to action games like Halo 2. Many action games require a lot of computing power, so they may not work unless you have a newer

Understanding Applications

What is an application?

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• Media Players: If you want to listen to mp3s or watchmovies that you've downloaded, you'll need to use amedia player. Windows Media Player and iTunes are popular media players.

• Gadgets: Sometimes called widgets, these are simple applications that you can place on your desktop (or on the Dashboard if you're using a Mac). There are many different types of gadgets, and they include calendars, calculators, maps, news headlines, and more

Installing Desktop Applications

In order to work, an application usually has to be installed on your computer. Typically, installation is as simple as inserting the installation disc and following the instructions on the screen. For software that is downloaded from the internet, you can usually double-click it after it is finished downloading, and then follow the instructions on the screen. Many applications include a readme file (for example, readme.txt), which includes installation instructions and other information.

v  Use caution when downloading software, as it can contain viruses or other malware. If you have an antivirusprogram, you should scan the downloaded software before installing it.

Opening Files with Applications

Many applications are designed to open one or more types of files (or file formats). For example, Microsoft Word can create and edit Word documents. If you don't have the right kind of application, you won't be able to open a file.

There are two main ways to open a file:

• Find the file on your computer, and double click it. This will open the file using the default program.

• Open the application, then use the application to open the file. Once the application is open, you can go to the File menu at the top of the screen and select Open. This is useful because some files can be opened by several different applications, and this method allows you to choose which application to use.

Web Apps and the Cloud

What is the Cloud?

You may have heard people using terms like the cloud, cloud computing, or cloud storage. But what exactly is the cloud? Basically, the cloud is the internet - more specifically, it's all of the things that you can access remotely over the internet. When something is in the cloud that means it is stored on servers on the internet, instead of on your computer. It lets you access your calendar, email, files and more, from any computer that has an internet connection.

If you've ever used web-based email, then you've used the cloud - all of the emails in your Inbox are stored on servers. However, there are many other services that use the cloud in different ways. Here are just a few examples:

• Dropbox is a cloud storage service that lets you easily store and share files with other people, and it lets you access your files from a mobile device as well.

• Evernote lets you type notes, clip web pages, take photos, and organize all of them from your computer or mobile device.

• Mozy and Carbonite can automatically back up your data in case your computer is lost, stolen, or damaged.

With the cloud, you're much less likely to lose your data, since it is stored on servers. However, just like anything online, there is always a risk that someone may try togain access to your personal data, so it's important to choose a strong password and pay attention to any privacy settings for the service you're using.

                                      

What is a Web App?

Previously, we talked about how desktop applications allow you to perform tasks on your computer. However, there are also web applications(or web apps), which run in the cloud and do not need to be installed on your computer. These are sometimes called cloud apps.

Examples of Web Apps

Here are a few examples of web apps:

• Online Email Services: Services like Yahoo! Mailand Gmail run within your browser and can do many of the same things that email programs likeMicrosoft Outlook can do. After you sign up for an online email service, you can begin using it immediately - no installation is required. Instead of being stored on your computer, your emails are stored in the cloud.

• Google Docs: Google Docs is an office suite that runs within your browser. Much like Microsoft Office, you can use it to create documents,spreadsheets, presentations, and more. Your documents are stored in the cloud, which makes it easy to share your documents with other people.

• Facebook: Facebook lets you create an onlineprofile and interact with your friends. Profiles and conversations are constantly evolving, so Facebook uses web app technologies throughout the site to keep the information up-to-date. There are also games and other web apps that you can add to your Facebook profile.

Web apps are becoming more and more integrated with websites, and it may be hard to distinguish between a web application and a "regular" website. In many cases, you may be using a web application without even knowing it!

How Do Web Apps Work?

When you use a web app, you are working from your computer or mobile device, but much of the actual processing is done by a network of servers. These servers can pool all of their processing power in order to handle requests from all over the world. They also use specialized servers to store the data that you're working with, as well as the data from all of the other users. All of this happens very seamlessly, so it looks almost like the application is running on your computer.

For example, if you open a document with Google Docs, your web browser will communicate with the network ofservers to display your document. As you edit the document, your browser will work closely with the servers to make sure everything is kept up-to-date.

Servers also play an important role in making the internet work: they are where web pages are stored. When you use your browser to click a link, a web server delivers the page you requested.

Other Types of Computers

Today, there are many different types of computers that you can buy, and some of them are even more portable than laptops. Here are a few common examples:

• Tablet Computers: These use a touch-sensitive screen for typing and navigation. Since they don't require a keyboard or mouse, tablet computers are even more portable than laptops. The iPad is an example of a tablet computer.

• Mobile Phones: Many mobile phones can do a lot of things a computer can do, such as browsing the internet or playing games. These phones are often called smartphones.

• Game Consoles: A game console is a specialized kind of computer that is used for playing video games. Although they are not as fully-featured as a desktop computer, many newer consoles, such as the Nintendo Wii, allow you to do non-gaming tasks like browsing the internet.

• TVs: Many TVs now include applications (or apps) that let you access various types of online content. For example, you can view your Facebook news feed or watch streaming movies on Netflix.

PCs and Macs

Personal computers come in two main "styles": PC and Mac. Both styles are fully functional, but they do have a different look and feel, and many people prefer one or the other.

• PC: This type of computer began with the original IBM PC that was introduced in 1981. Other companies began to create similar computers, which were called IBM PC Compatible (often shortened to PC). Today, this is the most common type of personal computer, and it typically includes the Microsoft Windowsoperating system.

• Mac: The Macintosh computer was introduced in 1984, and it was the first widely sold personal computer with a Graphical User Interface, or GUI (pronounced gooey). All Macs are made by one company, Apple Inc., and they almost always use the Mac OS X operating system.

Although PC can refer to an IBM PC Compatible, the term can also be used to refer to any personal computer, including Macs.

Understanding Operating Systems

What is an Operating System?

An operating system is the most important software that runs on a computer. It manages the computer's memory, processes, and all of its software and hardware. It also allows you to communicate with the computer without knowing how to speak the computer's "language." Without an operating system, a computer is useless.

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The Operating System's Job

You've probably heard the phrase boot your computer, but do you know what that means? Booting is the process that occurs when you press the power button to turn your computer on. During this process (which may take a minute or two), the computer does several things:

• It runs tests to make sure everything is working correctly.
• It checks for new hardware.
• It then starts up the operating system.

Once the operating system has started up, it manages all of the software and hardware on the computer. Most of the time, there are many different programs running at the same time, and they all need to access your computer's Central Processing Unit (CPU), memory, and storage. The operating system coordinates all of this to make sure that each program gets what it needs. Without the operating system, the software wouldn't even be able to talk to the hardware, and the computer would be useless.

Types of Operating Systems

Operating systems usually come preloaded on any computer that you buy. Most people use the operating system that comes with their computer, but it is possible to upgrade or even change operating systems.

The three most common operating systems for personal computers are Microsoft Windows, Apple Mac OS X, and Linux.

Modern operating systems use a Graphical User Interface, or GUI (pronounced "gooey"). A GUI lets you use your mouse to click on icons, buttons, and menus, and everything is clearly displayed on the screen using a combination of graphics and text.

Each operating system's GUI has a different look and feel, so if you switch to a different operating system it may seem unfamiliar at first. However, modern operating systems are designed to be easy to use, and most of the basic principles are the same.

Before GUIs, computers had a command-line interface, which meant the user had to type every single command to the computer, and the computer would only display text.

Microsoft Windows

Microsoft created the Windows operating system in the mid-1980s. Over the years, there have been many different versions of Windows, but the most popular ones are Windows 7 (released in 2009), Windows Vista (2007), and Windows XP (2001). Windows comes preloaded on most new PCs, which helps to make it themost popular operating system in the world.

If you're buying a new computer or upgrading to a new version of Windows, you can choose from several different editions of Windows, including Home Premium, Professional, and Ultimate. For most users, Home Premium offers enough features, but many people choose one of the more expensive editions.

THE END

In next Lecture 

DESKTOP COMPUTERS 

will be discussed in details.

Why Use the Cloud?

There are many reasons to use the cloud, but the main reasons are convenience and reliability. In the past, if you wanted to bring a file with you, you would have to save it to a USB flash drive, external hard drive, or CD-R disc. Saving a file to the cloud ensures that you'll be able access it with any computer that has an internet connection, so you don't have any physical media to keep track of. The cloud also makes it much easier to share a file with coworkers or friends, making it possible to collaborate over the internet.