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Chapter 4 Hardware, Software, and Mobile Systems
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Most industry observers would agree that Apple has led the way, both with the Mac OS and the
iOS, in creating easy-to-use interfaces. Certainly, many innovative ideas have first appeared in a Macin-
tosh or iSomething and then later were added, in one form or another, to Android and Windows.
Users who want Windows 10 on mobile devices will get either Windows 10 (mobile) on smart-
phones or a full version of Windows 10 on Surface Pro devices. Windows garners about 2 percent of
the mobile OS market share.
The smartphone market has always been huge, but recently, e-book readers and tablets
have substantially increased the market for mobile client operating systems. As of April 2015,
64 percent of Americans owned a smartphone, and 53 percent owned a tablet in addition to their
smartphone. 25

Server Operating Systems

The last three rows of Figure 4-10 show the three most popular server operating systems. Windows
Server is a version of Windows that has been specially designed and configured for server use. It has
much more stringent and restrictive security features than other versions of Windows and is popular
on servers in organizations that have made a strong commitment to Microsoft.
Unix can also be used on servers, but it is gradually being replaced by Linux.
Linux is frequently used on servers by organizations that want, for whatever reason, to avoid a
server commitment to Microsoft. IBM is the primary proponent of Linux and in the past has used it as
a means to better compete against Microsoft. Although IBM does not own Linux, IBM has developed
many business systems solutions that use Linux. By using Linux, neither IBM nor its customers have
to pay a license fee to Microsoft.

Virtualization
Virtualization is the process by which one physical computer hosts many different virtual (not
literal) computers within it. One operating system, called the host operating system, runs one
or more operating systems as applications. Those hosted operating systems are called virtual
machines (vm). Each virtual machine has disk space and other resources allocated to it. The
host operating system controls the activities of the virtual machines it hosts to prevent them from
interfering with one another. With virtualization, each vm is able to operate exactly the same as it
would if it were operating in a stand-alone, nonvirtual environment.
Three types of virtualization exist:
• PC virtualization
• Server virtualization
• Desktop virtualization
With PC virtualization, a personal computer, such as a desktop or laptop, hosts several
different operating systems. Say a user needs to have both Linux and Windows running on a com-
puter for a training or development project. In that circumstance, the user can load software like
Oracle VirtualBox or VMWare Workstation on the host operating system in order to create Linux
and Windows virtual machines. The user can run both systems on the same hardware at the same
time if the host operating system has sufficient resources (i.e., memory and CPU power) as shown
in Figure 4-12.
With server virtualization, a server computer hosts one or more other server computers.
In Figure 4-13, a Windows Server computer is hosting two virtual machines. Users can log on
to either of those virtual machines, and they will appear as normal servers. Figure 4-14 shows
how virtual machine VM3 appears to a user of that server. Notice that a user of VM3 is running
a browser that is accessing SharePoint. In fact, this virtual machine was used to generate many
of the SharePoint figures in Chapter 2. Server virtualization plays a key role for cloud vendors, as
you’ll learn in Chapter 6.