S

scalability

A measure of how well a computer, service, or application can grow to meet increasing performance demands. For server clusters, the ability to incrementally add one or more systems to an existing cluster when the overall load of the cluster exceeds its capabilities. See also server cluster.

schema

The set of definitions for the universe of objects that can be stored in a directory. For each object class, the schema defines which attributes an instance of the class must have, which additional attributes it can have, and which other object classes can be its parent object class. See also parent object.

scope

A range of IP addresses that are available to be leased or assigned to DHCP clients by the DHCP service. See also Dynamic Host Configuration Protocol (DHCP); IP address; lease.

script

A type of program consisting of a set of instructions to an application or tool program. A script usually expresses instructions by using the application s or tool s rules and syntax, combined with simple control structures such as loops and if/then expressions. Batch program is often used interchangeably with script in the Windows environment.

secure dynamic update

The process in which a DNS client submits a dynamic update request to a DNS server and the DNS server performs the update only if the client is authenticated. See also DNS server; dynamic update.

Secure Sockets Layer (SSL)

A protocol that supplies secure data communication through data encryption and decryption. SSL uses RSA public-key encryption for specific TCP/IP ports. It is intended for handling commerce payments. An alternative method is Secure-HTTP (S-HTTP), which is used to encrypt specific Web documents, rather than the entire session. SSL is a general-purpose encryption standard. SSL can also be used for Web applications that require a secure link, such as e-commerce applications, or for controlling access to Web-based subscription services.

security

On a network, protection of a computer system and its data from harm or loss, implemented especially so that only authorized users can gain access to shared files. See also authorization.

security group

A group that can be listed in discretionary access control lists (DACLs) used to define permissions on resources and objects. A security group can also be used as an e-mail entity. Sending an e-mail message to the group sends the message to all the members of the group. See also group.

server

In general, a computer that provides shared resources to network users. See also client.

server certificate

A unique digital identification that forms the basis of a Web server s Secure Sockets Layer (SSL) security features. Server certificates are obtained from a mutually trusted, third-party organization, and they provide a way for users to authenticate the identity of a Web site.

server cluster

A group of computers, known as nodes , working together as a single system to ensure that mission-critical applications and resources remain available to clients. A server cluster presents the appearance of a single server to a client. See also cluster.

service

A program, routine, or process that performs a specific system function to support other programs, particularly at a low (close to the hardware) level. When services are provided over a network, they can be published in Active Directory, facilitating service-centric administration and usage. Some examples of services are the Security Accounts Manager service, File Replication service, and Routing and Remote Access service. See also File Replication service (FRS).

Service Pack

A software upgrade to an existing software distribution that contains updated files consisting of patches and hot fixes.

Setup

The program that installs Windows. Also known as unattended installation , Winnt32.exe , and Winnt.exe .

shared folder

A folder on another computer that has been made available for other people to use on the network.

shortcut

A link to any item accessible on your computer or on a network, such as a program, file, folder, disk drive, Web page, printer, or another computer. You can put shortcuts in various areas, such as on the desktop, on the

Start

menu, or in specific folders.

Simple Mail Transfer Protocol (SMTP)

A TCP/IP protocol for sending messages from one computer to another on a network. This protocol is used on the Internet to route e-mail.

Simple Network Management Protocol (SNMP)

A network protocol used to manage TCP/IP networks. In Windows, the SNMP service is used to provide status information about a host on a TCP/IP network. See also protocol; service; Transmission Control Protocol/Internet Protocol (TCP/IP).

site

One or more well-connected (highly reliable and fast) TCP/IP subnets. A site allows administrators to configure Active Directory access and replication topology to take advantage of the physical network. See also Active Directory; subnet; Transmission Control Protocol/Internet Protocol (TCP/IP).

smart card

A credit card “ sized device that is used with an access code to enable certificate-based authentication and single sign-on to the enterprise. Smart cards securely store certificates, public and private keys, passwords, and other types of personal information. A smart card reader attached to the computer reads the smart card.

SMS

See definition for Systems Management Server (SMS).

snap-in

A type of tool that you can add to a console supported by Microsoft Management Console (MMC). A stand-alone snap-in can be added by itself; an extension snap-in can be added only to extend the function of another snap-in. See also Microsoft Management Console (MMC).

sniffer

An application or device that can read, monitor, and capture network data exchanges and read network packets. If the packets are not encrypted, a sniffer provides a full view of the data inside the packet. See also packet.

software metering

The process by which SMS monitors program usage on client computers.

static page

A Hypertext Markup Language (HTML) page that is prepared in advance of a request for it and that is sent to the client upon request. This page takes no special action when it is requested . See also dynamic page.

stripe set

A volume that stores data in stripes on two or more physical disks. A stripe set is created by using Windows NT 4.0 or earlier. Windows XP and Windows Server 2003 do not support stripe sets. Instead, you must create a striped volume on dynamic disks. See also dynamic disk.

subkey

An element of the registry that contains entries or other subkeys. A tier of the registry that is immediately below a key or a subtree (if the subtree has no keys). See also key; registry.

subnet

A subdivision of an Internet Protocol (IP) network. Each subnet has its own unique subnetted network ID. See also Internet Protocol (IP).

subnet mask

A 32-bit value that enables the recipient of Internet Protocol version 4 (IPv4) packets to distinguish the network ID and host ID portions of the IPv4 address. Typically, subnet masks use the format 255. x . x . x . IPv6 uses network prefix notations rather than subnet masks. See also IP address.

superscope

An administrative grouping feature that supports a DHCP server s ability to use more than scope for each physical interface and subnet. Superscopes are useful under the following conditions: If more DHCP clients must be added to a network than were originally planned, if an Internet Protocol (IP) network is renumbered, or if two or more DHCP servers are configured to provide scope redundancy and fault-tolerant design DHCP service for a single subnet. Each superscope can contain one or more member scopes (also known as child scopes ). See also fault tolerance; scope; subnet.

switch

A computer or other network-enabled device that controls routing and operation of a signal path . In clustering, a switch is used to connect the cluster hosts to a router or other source of incoming network connections.

Syspart

A process that executes through an optional parameter of Winnt32.exe. Used for clean installations to computers that have dissimilar hardware. This automated installation method reduces deployment time by eliminating the file-copy phase of Setup.

Sysprep

A tool that prepares the hard disk on a source computer for duplication to destination computers and then runs a non-Microsoft disk-imaging process. This automated installation method is used when the hard disk on the master computer is identical to those of the target computers. See also destination computer.

system volume

The volume that contains the hardware-specific files that are needed to load Windows on x86-based computers with a basic input/output system (BIOS). The system volume can be, but does not have to be, the same volume as the boot volume. See also basic input/output system (BIOS).

systemroot

The path and folder name where the Windows system files are located. Typically, this is C:\Windows, although you can designate a different drive or folder when you install Windows. You can use the value %systemroot% to replace the actual location of the folder that contains the Windows system files. To identify your systemroot folder, click Start, click Run, type %systemroot% , and then click OK.

Systems Management Server (SMS)

A Microsoft product that includes inventory collection, software deployment, and diagnostic tools. SMS automates the task of upgrading software, allows remote problem solving, provides asset management information, and monitors software usage, computers, and networks.