where the networks might use different protocols. The router
forwards only those messages that need to be forwarded from one
network to another. See alsoGateway.
RSS reader Software built into today’s browsers and some
e-mail programs that—after a user has subscribed to an RSS feed
from a particular site—checks for new content at user-determined
intervals and retrieves syndicated Web content such as Weblogs,
podcasts, and mainstream mass media reports.
SA&D SeeSystems analysis and design.
SaaS SeeSoftware as a Service.
Sarbanes-Oxley Act (SOX) Legislation passed by the U.S.
government in 2002 that requires stricter accounting procedures
and financial record certifications for publicly traded corpora-
tions in response to recent corporate scandals in large U.S.
companies (such as Enron). The passing of this act led to signifi-
cant investments in information technologies by many companies
to implement better controls to ensure the reliability and integrity
of enterprise data.
Satellite communication A variation of microwave transmis-
sion in which a communications satellite is used to relay
microwave signals over long distances.
Satellite connection A high-speed, or broadband, connection
to the Internet using a satellite dish at the home or office to com-
municate with a satellite.
SCM SeeSupply chain management system.
Scrum One of the so-called “agile” methodologies in which small
work teams, utilizing frequent and varied meetings, coordinate a
series of very small projects that together develop an information
system.
SDLC SeeSystem development life cycle.
Search engine An information retrieval program that permits
the user to search for content that meets a specific criterion
(typically containing a given word or phrase) and retrieves a list
of items that match the criterion.
Sequential access file A basic type of computer file in which
all of the records that make up the file are stored in sequence
according to the file’s control key (e.g., a payroll file will contain
individual employee records stored in sequence according to the
employee identification number); usually stored on magnetic
tape. Computer files, also called secondary memory or secondary
storage, are added to a computer system to keep vast quantities of
data accessible within the computer system at more reasonable
costs than main memory.
Server operating system Support software installed on the
network server that manages network resources and controls the
network’s operation. The primary server operating systems are
Microsoft’s Windows Server, especially Windows Server 2008,
several variations of UNIX, and Linux.
Server virtualization In this popular type of virtualization, a
physical server is split into multiple virtual servers, each of which
can run its own full-fledged operating system. The physical
server typically runs a hypervisor program to create the virtual
servers and manage the resources of the various operating
systems. Then each virtual server can be employed as if it were a
Glossary 685stand-alone physical server, thus reducing the number of physical
servers needed in an IT shop and saving the organization money
and space.
Service-oriented architecture An application architecture
based on a collection of functions, or services, where these
services can communicate (or be connected) with one another.
Once services are created, they can be used over and over again in
different applications—only the connections will vary.
Service level agreement (SLA) An agreement between IS and
a client that specifies a set of services to be provided, the amount
of those services to be provided, the quality of these services and
how it is to be measured, and the price to be charged for these
services.
Servlet An application program, written in the Java object-
oriented programming language, which resides on a Web server
and is executed on the Web server (not downloaded to the client
like an applet). See alsoApplet.
SFC SeeShop floor control.
Shared Ethernet The original Ethernet design, which employs
a contention bus as its logical topology but is usually implement-
ed as a physical star arrangement. The usual way of creating a
shared Ethernet LAN is to plug the cables from all the devices on
the LAN into a hub, which is a junction box containing up to
24 ports into which cables can be plugged. Embedded inside the
hub is a linear bus connecting all the ports. See alsoEthernet,
Switched Ethernet.
Shared services A type of centralized governance design in
which IS decision making and accountability are “shared” across
multiple business units. Shared services units are often respon-
sible for not only IS activities (typically computer and network
operations) but also other functional support activities—such
as entities responsible for recruiting and retaining human
resources.
Shop floor control (SFC) system A computer-based system
that provides online, real-time control and monitoring of
machines on the shop floor; for example, the SFC system
might recognize that a tool on a particular milling machine is
getting dull (by measuring the metal that the machine is
cutting per second) and signal this fact to the human operator
on duty.
Simplex transmission A type of data transmission in which
data can travel only in one direction over the communication line.
Simplex transmission might be used from a monitoring device at
a remote site back to a central computer.
SLA SeeService level agreement.
Smartphone A handheld computer which also operates as a
cellular telephone; such a device permits the user to make phone
calls, pick up and send e-mail, manage your calendar, keep your
to-do list and address book up to date, take pictures, and be enter-
tained with games, music, and video, as well as a wide variety of
other functions.
SMP SeeSymmetric multiprocessor.
SNA SeeSystems Network Architecture.