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Q1 What Do Business Professionals Need to Know About Computer Hardware? 117

prominence with the iPad. In 2012, Microsoft announced Surface and Google announced the
Nexus series, all tablets. Smartphones are cell phones with processing capability; the Samsung
Galaxy S5 is a good example. Today, because it’s hard to find a cell phone that isn’t “smart,”
people often just call them phones.
A server is a computer that is designed to support processing requests from many re-
mote computers and users. A server is essentially a PC on steroids. A server differs from a PC
principally because of what it does. The relationship between PCs and servers is similar to the
relationship between clients and servers at a typical restaurant. Servers take requests from
clients and then bring them things. In restaurants this is food and silverware. In computing
environments servers can send Web pages, email, files, or data to PCs. PCs, tablets, and smart-
phones that access servers are called clients. As of 2014, a good example of a server is the Dell
PowerEdge server.
Finally, a server farm is a collection of, typically, thousands of servers. (See Figure 4-2.)
Server farms are often placed in large truck trailers that hold 5,000 servers or more. Typically
a trailer has two large cables coming out of it; one is for power, and the other is for data com-
munications. The operator of the farm backs a trailer into a pre-prepared slab (in a warehouse
or sometimes out in the open air), plugs in the power and communications cables, and, voilà,
thousands of servers are up and running!
Increasingly, server infrastructure is delivered as a service via the Internet that is often re-
ferred to as the cloud. We will discuss cloud computing in Chapter 6, after you have some knowl-
edge of data communications.
The capacities of computer hardware are specified according to data units, which we dis-
cuss next.

Computer Data

Computers represent data using binary digits, called bits. A bit is either a zero or a one.
Bits are used for computer data because they are easy to represent physically, as illustrated
in Figure 4-3. A switch can be either closed or open. A computer can be designed so that an
open switch represents zero and a closed switch represents one. Or the orientation of a mag-
netic field can represent a bit: magnetism in one direction represents a zero; magnetism in
the opposite direction represents a one. Or, for optical media, small pits are burned onto the

Figure 4-2
Server Farm
Source: © Andrew Twort/Alamy