How Windows 8 Works

There are two main layouts for Windows 8 -- the desktop and the tiled Windows 8 interface formerly known as Metro. The desktop environment will look somewhat familiar to anyone who has used a Windows-based computer over the last few years. You can create shortcuts to applications on the desktop. Clicking an icon will launch the respective program.

But the big news is the tiled interface. In a dramatic departure from traditional computer-OS design, this interface looks like it belongs on a tablet or smartphone. That's no accident. Recent trends show a decline in PC sales as customers turn their attention to mobile devices [source: Tyson]. But while we've seen big improvements in mobile designs and capabilities, there are still some types of software that work best on a full PC.

Windows 8 bridges the gap between PC and mobile operating systems. Microsoft optimized Windows 8's interface to work with touch-screen devices and displays. As mobile devices become more sophisticated, they could potentially replace PCs entirely. By creating an operating system that can work across platforms, Microsoft is attempting to cater to all customers.

If you have a touch-capable device or display, you can navigate Windows 8 with touch gestures. Tapping on a tile will open a corresponding application. Swiping the screen will let you navigate through apps or pull up the Charms menu from the edge of the screen. Microsoft places popular tools in the Charms menu, such as the search interface.

If you don't have a touch-capable device, you can still use the tiled interface with a mouse and keyboard. Instead of activating special commands with gestures, you have to place your cursor in one of several activation points to pull up particular menus or commands. You can use a scroll bar at the base of the screen to navigate left and right through the tiles.

Those tiles aren't just icons that will launch a program. Microsoft allows app developers to deliver information through tiles even when an app isn't active. The company calls the feature "live tiles." A live tile can display notifications relevant to the app.

The tiled interface of Windows 8 houses apps. Technically, an app is a type of software. But you'll often hear the two terms used as if they mean different things. In Windows 8, there's a big difference.

In general, an app is a piece of software that is relatively easy to install and use. Most apps have a fairly limited set of features. Part of that is to keep the app's file size small. Another reason for limited features is to prevent the app from becoming so complicated that it becomes difficult to use. In general, developers try to optimize apps to deliver a particular experience by playing to the strengths of a particular platform or operating system.

If Windows 8 were only meant for touch-screen devices, developers would only need to focus on how to create an app that works well with touch and gesture commands. But because Windows 8 also works on PCs that don't have touch screens, the mouse-and-keyboard users need to be considered during development, too.

What about software? While the word can mean any type of computer application, in general we now use the term to mean larger, more complex computer programs. These programs may have features that require more support than what the tiled interface can provide. They could require complex keystrokes or include deep menu systems that would be difficult or impossible to navigate in the tiled environment on Windows 8. These programs belong on the desktop.

The desktop environment of Windows 8 supports full programs. Some of these programs have app counterparts with fewer features or simplified interfaces. While the desktop looks more like previous versions of Windows, there are some major differences.

One of those is the lack of a Start button. Microsoft first introduced the Start button with Windows 95. For some users, its disappearance may be unsettling. You can find much of the functionality of the Start menu through the Start screen in the tiled interface. Clicking on a Windows button -- if your keyboard has one -- will switch between the desktop and tiled interfaces. Otherwise, moving your mouse cursor to the lower left corner of the screen brings up a Start screen icon.

Perhaps the most important role of the desktop environment is to act as a platform for older programs that have no app counterpart at all and which cannot run within the tiled interface. You may have a collection of legacy programs you depend upon regularly. The desktop environment helps ensure that Windows 8 is relevant to customers who need access to older programs.

Mobile apps and computer software often have different interfaces. In the traditional desktop environment, it's possible to multitask and run several programs at once. Each program runs within its own window. You can resize windows and have several programs in view at the same time.

The OS handles multitasking by managing and directing resources to each running application. The more programs you activate at once, the more work your computer has to do to keep them running. And if you're using several processor or memory-intensive programs at once, you may find progress slowing to a crawl.

In general, modern desktop and laptop computers can handle a reasonable load of multitasking because they tend to have enough memory and processor power for the job. But the apps that run on mobile devices are usually more limited. They may not have as much memory or horsepower as a PC to dedicate to multiple running processes.

Apps tend to take up an entire screen's worth of landscape. Most operating systems that run apps only allow you to view one active app at a time, even if the OS supports multiple running apps. You may be able to switch from one app to another seamlessly, but you can't view more than one at any given moment.

The tiled interface for Windows 8 works more like the second method -- the running app takes center stage. But you can make it act a little like the desktop environment with a feature Microsoft calls Snap. Snap lets you assign an app running in the background to either the left or right side of the screen while the app you're running in the foreground takes up most of the screen's real estate.

Microsoft also lets you Snap your desktop to the side of the screen. This will let you see all applications your computer is currently running. It's like the application tabs in older versions of the operating system.

The Snap version of an app may have only a few features -- such as notifications -- enabled. You'll be able to see both apps at the same time, but you may not have access to each app's full functionality the way you would with software windows in desktop mode.

Delivering a common experience across multiple devices requires more than just an operating system that can handle mouse-and-keyboard or touch commands. To be able to move seamlessly from one device to another, you have to make sure all your apps and data are accessible across each device. Just a few years ago, that would require you to save data to some form of removable data storage and transfer it physically to another machine.

Microsoft made a shift to the cloud with Windows 8. The cloud is a general term for networked computers that store data and applications on them. Saving data to the cloud means that you can access the information with any gadget capable of connecting to the cloud network.

In Windows 8, a user must create a profile that includes access to Microsoft's cloud network. Signing on from any Windows 8 device will give you access to your apps and data as if it were your primary machine. Windows 8 apps run directly on user devices. That means that signing into a Windows 8 machine with your account will give you access to your apps, but you'll have to download them to the machine first.

For people who are particular about their OS settings, Windows 8 cloud synchronization is a welcome addition. Setting features like desktop themes, language and preferred browser on one Windows 8 device creates the foundation. When you log in from a different Windows 8 device, the OS applies your preferences from the other machine. This even applies to browser history, so if you want to show someone that funny cat video you looked at on a completely different computer, you still have that option.

As anyone who has watched the infamous YouTube clip of Steve Ballmer rallying an audience at a conference several years ago knows, Microsoft values developers. The company created a suite of tools and resources for anyone interested in building apps for Windows 8.

There are three main pathways developers can take when building an app. The first option is to design apps using hypertext markup language 5 (HTML5), Cascading Style Sheets (CSS) and JavaScript. These are the same tools you'd use to create a dynamic Web page. This is a good choice for developers who want to port a Web site experience into an app.

The second method is to build an app using a more traditional programming language. Programmers who want to jump into Windows 8 app development can build their apps with C++, C# or Visual Basic. These languages allow developers to create Silverlight, .NET and Windows Presentation Foundation applications.

The third method requires developers to build an app using DirectX, a suite of interfaces useful for creating multimedia applications. On the back end, developers will build their apps using C++ and HLSL.

Any developer who wants to submit an app to the Windows Store needs to download Windows 8 and the suite of developer tools Microsoft makes available for free. These include Microsoft Visual Studio and the software development kit (SDK) for Windows 8. The developer will also need to apply for a developer license, which is free.

There are several guides -- both created by Microsoft and by third parties -- that explain how to create an app and give plenty of tips and tricks. Microsoft built some guidelines directly into Windows 8, including a grid layout that lets app developers arrange the graphics and text in their apps so that the app is both attractive and functional.

Microsoft conducted research with focus groups to learn how people interact with touch-screen interfaces, including tablets. They looked for patterns to determine where to locate controls and commands. The company makes the research available to app developers to help them design apps optimized for Windows 8.

Once a developer has built and tested an app, it's time to submit it to the Windows Store. Microsoft conducts its own tests to make sure apps work properly. Assuming everything checks out and the app doesn't violate any of Microsoft's policies, it will appear in the Windows Store as an available download.

App developers have options for monetizing their apps. They can charge a fee for the app, include in-app purchases or use advertising to generate revenue. As part of the app developer's agreement with Microsoft, which every developer must agree to before their apps will appear in the store, Microsoft gets 30 percent of the revenue generated by an app. If an app generates at least $25,000 in revenue Microsoft will drop the fee to 20 percent [source: Microsoft].

So what's really going on beneath all the tiles and desktops? First, Windows 8 is actually version 6.2 of Windows, according to Microsoft. Windows XP is version 5.1, Windows Vista was 6.0 and Windows 7 is 6.1. Why is there a discrepancy between the version number and the name?

Part of the answer is to prevent application errors. Some applications contain code that sets an upper limit on the OS version number. The code might let the application run on a version 6.x machine but not on a 7.x computer.

Why set version limits at all? A cynic might say it helps guarantee a customer base for future versions of the software by forcing people to buy new versions as they upgrade their machines. But another reason is that some applications depend upon certain OS features, and using the OS version number as a guide is a shortcut to making sure those features are present.

Microsoft advises against this approach. The company urges developers to create tests to check for specific features instead of looking at the OS version number [source: Microsoft].

Microsoft built Windows 8 to run on devices with an Intel processor with either a 32-bit or 64-bit architecture. The architecture is an instruction set designed to move operations and data through a particular way. Because of this, Windows 8 will not run on a computer with a processor built on a different architecture.

To run Windows 8, your computer must meet a few minimum hardware requirements. You'll need a machine with:

To take full advantage of Windows 8, you'll need a device with a touch interface.

Microsoft's move with Windows 8 marks a big change in computing in general as we move to smaller, more mobile form factors. Will we see future operating systems follow the same path?