Читать книгу IC3: Internet and Computing Core Certification Global Standard 4 Study Guide - Ciprian Adrian Rusen - Страница 8

We will start by defining hardware, software, and operating systems so that you have a good understanding on what they are and what their role is. As you will see, the relationship between them is quite delicate and very important. Any computer or device cannot function and cannot be used productively without these three elements working well together. That's why we will start by discussing them and by explaining all the key concepts that are involved.

What Is Hardware?

Any computer or device is composed, at a physical level, of hardware. For example, a computer almost always has a monitor, a mouse and keyboard, a hard disk or flash memory, a graphics card, a sound card, some memory, a motherboard, a network card, a case, and a power supply.

If you look inside a smartphone and a tablet, you will find similar components. The most important difference is their size, since they need to fit into a person's hand. Also, the display is touch sensitive, and mobile devices have a battery built in.

Each hardware component is specialized to perform a set of specific tasks. For example, the sound card is in charge of providing sound to the user, the graphics card takes care of processing the image and sending it to display, the network card is in charge of connecting to the network and the Internet, and so on.

What Is Software?

Software is a set of machine-readable instructions that direct a computer or device to perform specific operations. Software is not physical like hardware is. It is ephemeral, in the sense that it is anything that can be stored electronically on the hardware of a computer or device.

There are many types of software, the most important being these two:

System Software This software is designed to directly operate the hardware of a computer or device. Such software provides all the basic functions that allow users and other software to control the device's hardware. The most common types of system software are the operating system, drivers (which control a specific hardware component), and system utilities (which assist users in the maintenance of their computers).

Application Software This is specialized software the users can employ to perform certain tasks. For example, Microsoft PowerPoint lets users create presentations. Antivirus software like Norton Antivirus or Kaspersky Antivirus keeps your computer safe from threats and so on. This type of software is also referred to as applications, programs, or apps (when working with mobile devices). In order to function, application software needs to run on top of both the system software and hardware. Applications are either provided by the operating system (for example, Paint is an application offered by Windows) or installed by users on top of the operating system.

To help you understand these concepts better, let's take a look at each of these two types of software in more detail.

What Is an Operating System?

An operating system is a special type of software that manages all the communications between the user, the software applications, and the hardware in a computer or device. It is the most important piece of software that runs on a device because without it interactions with that device would be impossible. Operating systems perform important tasks like recognizing the hardware components of a device, controlling them, taking input from devices such as the keyboard or the touch screen (in the case of tablets and smartphones), managing the file system on that device, taking input from the user or from other software applications, and sending it to the hardware.

The most popular operating systems are Windows, Linux, Mac OS X, Android, iOS, and Windows Phone. Some are designed to work on computers and laptops (Windows, Linux, or Mac OS X), while others are designed to work on mobile devices like smartphones and tablets (Android, iOS, Windows Phone).

Operating systems have many characteristics that allow them to be classified in multiple ways. The most important characteristics are these:

■ Modern operating systems are real-time.

They execute applications and commands in real time. The benefit of being real-time is that the operating system delivers a quick and predictable response to the commands issued by the user or by the applications they are using.

■ Modern operating systems are multitasking.

They allow multiple applications to run at the same time. Hardware resources are allocated and managed automatically by the operating system and shared among all the programs and services that are running.

■ Operating systems can be multiuser or single-user.

For example, Windows and other operating systems that are designed to run on computers are multiuser. This means that you can create multiple user accounts on the same computer and have them share that computer's hardware and software resources. Single-user operating systems allow only one user account. Generally, these operating systems are found on mobile devices like smartphones and tablets. However, even these types of devices will have multiuser operating systems in the future.

■ Some operating systems can be embedded.

This means that they are designed to be used in small devices like cash registers, ATMs, and so on. These devices are very compact and have limited resources. Embedded operating systems are optimized to run on limited hardware resources, and they generally provide a small and specialized set of services and interactions.

How Do They All Work Together?

When you start a computer or a device like your smartphone, the operating system loads first. Once that is loaded, you will interact with both the application software that is installed on it and the operating system. For example, when you use an application like Microsoft Word to write a document, the application sends your input and commands to the operating system. The operating system then communicates with the hardware, and it automatically manages the resources used by Microsoft Word in order to deliver the desired results.

Users can also work directly with the operating system. For example, in Windows, you can access the files and folders that are stored on your computer and open them. You can also browse the storage on your computer, using the operating system and its features, without needing to install other applications.

Figure 1.1, which shows how the operating system and system software are layered on a typical computer, should help you understand this more clearly. The arrows indicate how the information flows.

FIGURE 1.1 The flow of information among the user, software applications, the operating system, and the hardware

Which Computer Operating System Is Best?

There is a never-ending debate about which is the best operating system for your computer. Is it Windows? Is it Mac OS X? Is it Linux? The truth is that modern operating systems are not that different anymore, at least not when it comes to what you can do with them. You can use any of them to write a document, deliver a presentation, play games, watch movies, surf the Internet, and so on. Very few features are unique to one operating system. The differences between them are mostly in the way the user interface works.

Choosing one operating system versus another is mostly a matter of personal preference. If you like how a Mac looks and feels, you might purchase a Mac and use Mac OS X. If you are a great believer in free software, then you might prefer to use Linux on your computer. If you want to have access to the greatest number of applications, devices, and learning resources, then you will go for Windows.

Accessing and Locking the Operating System

When you press the power button on a computer or other device, the operating system is loaded, and you're asked to sign in if you've set up a password or personal identification number (PIN). Regardless of the device, the basic idea is the same: you need to power up your computer or device, wait for the operating system to load, and then authenticate yourself in order to use it.

If you have only one user account on your computer and no password set for it, it is enough to press the power button on your computer and wait for Windows 7 to start and automatically sign you in. However, not having a password makes your computer a lot less secure, and we recommend that you always set a password for your user account.

Let's do an exercise together in which you'll learn how to power on your computer and sign into Windows 7 (Exercise 1.1).

EXERCISE 1.1

Signing into Windows 7

1. Press the power button on your computer.

2. Wait for the operating system to start.

When that process is finished, you are shown the sign-in screen (Figure 1.2), where you can see the user accounts that exist on your computer.

3. Select your user account and then type your password.

If you have only one user account on your Windows 7 computer, you are directly prompted for your password, without having to go through this step. Also, if you have no password set for your account, then you won't be asked to type one.

4. Click the sign-in button, which is an arrow pointing to the right (Figure 1.3).

FIGURE 1.2 The Windows log-in screen showing the user accounts that exist on your computer

FIGURE 1.3 The sign-in screen for your user account

Once you log into Windows 7, you can start using the software applications that are installed on it and do your work. When you have finished working on the computer, you can do the following:

Switch User You can switch to another user account that exists on your computer so that someone else can use it. When you do this, your account remains active in the background and so do all your running applications. They will be available to you in the state in which you left them when you switch back to your user account. Be aware that other users can turn off the computer, and your unsaved work will be lost if that happens.

Log Off All your applications and files are closed. The computer and the operating system remain turned on, and other users can log in with their accounts and continue using the computer.

Lock Your user account remains active in the background as well all your running applications. Windows 7 displays the sign-in screen and requests your user account password. You can unlock your account by typing your password, and you will be able to resume your work exactly where you left off. No one else can use your account and your running applications unless they type your password and unlock your account.

Restart All your applications and files are closed. The operating system is shut down and then your computer and the operating system are restarted. When the restarting procedure is over, you are back to the sign-in screen, where you can log back into Windows.

Sleep Sleep is a low-power mode that saves significantly on power consumption. Your user account gets locked, Windows stores your work in memory, and then it places itself into stand-by mode. When you press the power button, Windows resumes from sleep and allows you to sign in and resume your work, exactly where you left off. Resuming from sleep is generally faster than powering on your computer.

Shut Down First, all your applications and files are closed. Then the operating system turns itself off as well as the computer. When shut down, the computer does not use electrical power because it is no longer running.

To access all these options, click the Start button to open the Start menu. On the right side you will see the Shut Down button and a small arrow near it. Clicking the Shut Down button will obviously power off your computer, as mentioned earlier. Clicking the small arrow near it will give you access to the additional options that were mentioned earlier, as shown in Figure 1.4.

FIGURE 1.4 Options for switching the user, logging off, locking the computer, restarting it, or putting it to sleep

To learn more, let's do this small exercise, which teaches you how to put Windows 7 to sleep and then resume from sleep (Exercise 1.2).

EXERCISE 1.2

Putting Your Computer to Sleep and Then Resuming Your Work

1. Click the Start button in Windows 7, on the bottom-left corner of the screen.

2. Click the small arrow near the Shut Down button to reveal other options (Figure 1.5).

3. Click Sleep and wait for Windows 7 to turn off the screen and put itself into sleep mode.

4. Wait a couple of seconds, press the power button, and then wait for Windows 7 to resume from sleep.

5. At the sign-in screen, type your user account password and click the Sign In button.

FIGURE 1.5 The Sleep button

Software and System Updates

Most applications and operating systems receive updates on a regular basis. Windows receives updates through the Windows Update service, whereas software applications receive updates through their own update services, if their manufacturer provides them. For example, Internet browsers made by companies other than Microsoft (e.g., Google Chrome, Mozilla Firefox, Opera) have their own update service. They are updated on a monthly basis because they require continuous improvement in order to keep up with the needs of their users and the evolution of the Internet. Other applications may not have their own update service, so users need to manually download and install newer versions when they become available. Most applications are like this, including popular ones like the 7-Zip file archiver or the GOM multimedia player.

Luckily, Microsoft also offers updates to popular software like Microsoft Office or Windows Essentials through the Windows Update service, if you set it to deliver them.

Software updates are created for many reasons:

■ To fix problems of any kind, ranging from security issues to bugs that don't allow the software run as it was intended.

■ To add new features and characteristics that make the product more useful to its users.

■ Some operating system updates also provide new driver versions that allow the operating system to better use and manage the hardware components of your computer.

By default, Windows is set to automatically check for updates and install them when they are available. However, you can also install them manually. Exercise 1.3 details how to check for updates and install those that are available.

EXERCISE 1.3

Manually Installing Windows Updates

1. Click Start and then Control Panel.

2. Click System And Security and then Windows Update (Figure 1.6).

3. In the column on the left, click Check For Updates (Figure 1.7).

4. Wait for Windows to check for updates and let you know whether there are any updates available to be installed.

5. If updates are available, click Install Updates (Figure 1.8) and wait for them to be installed.

When the process is finished, you are informed that the updates were successfully installed.

6. It is possible that Windows will recommend that you restart your computer in order to install those updates. If that is the case, click Restart Now (Figure 1.9). Otherwise, close the Windows Update window.

FIGURE 1.6 The System And Security section in Control Panel

FIGURE 1.7 The Windows Update window

FIGURE 1.8 Windows Update informing you how many updates are available

FIGURE 1.9 Windows Update informing you that updates were successfully installed

Always Keep Windows Update Turned On

On some technical forums or blogs you may encounter a recommendation to disable Windows Update. Some recommend this because they think that it improves general system performance. Others recommend this because using Windows Update on pirated copies of Windows will install updates that figure out whether users are using an illegal copy of Windows and try to inform them about this problem and educate them on how to purchase a legal copy of Windows.

Disabling Windows Update is a very bad practice that only creates problems for users. For starters, your Windows installation will not benefit from the many security updates provided by Microsoft. Therefore, it will be vulnerable to all kinds of security threats. Also, you won't benefit from bug fixes and performance improvements. Also, some updates add new features to Windows that may be useful to you. That's why you should always check and confirm that Windows Update is enabled on your computer and that it installs updates automatically.

Windows Update can be set to work in four different ways:

■ Install Updates Automatically (Recommended)

Every day, Windows automatically checks for updates and installs them in the background when they are available. If a computer restart is required in order to finalize their installation, it will request it from the user. This is the default setting for Windows Update.

■ Download Updates, But Let Me Choose Whether to Install Them

Windows Update automatically checks for updates and downloads them in the background when they are available. The user is prompted to install them, when appropriate.

■ Check For Updates, But Let Me Choose Whether to Download and Install Them

Windows Update automatically checks for updates in the background, and it informs the user when they available for download and installation. It doesn't download any updates without the user's prior consent.

■ Never Check For Updates (Not Recommended)

This means that Windows Update is turned off and not working. Windows is not kept up to date, and it becomes vulnerable to all kinds of problems.

When setting up your Windows computer for the first time, it is a good idea to double-check that Windows Update is turned on and working well. Exercise 1.4 shares how to do this.

EXERCISE 1.4

Confirming That Windows Update Is Turned On

1. Click Start and then Control Panel.

2. Click System And Security and then Windows Update.

3. In the column on the left, click Change Settings.

4. In the Important Updates section, select Install Updates Automatically (Recommended) (Figure 1.10).

5. Click OK.

6. Close the Windows Update window.

FIGURE 1.10 Where you change the Windows Update settings