S

scalable font

A TrueType font. See also TrueType font.

scaling

A transformation that alters the apparent size of an object.

scan code

A device-dependent value that identifies a physical key on the keyboard. Each key on a keyboard generates two unique scan codes--one when the user presses the key and the other when the user releases the key.

scan line

A single row of adjacent pixels on a video display. See also pixel.

scheduler

The component of the operating system that determines which of the competing threads receives the next slice of the processor's time. See also thread.

screen buffer

A two-dimensional array of character and color data for output in a console window. A screen buffer can be accessed for reading and writing whether it is active or inactive. Its character data can be either a Unicode™ or ANSI value. See also console window.

screen coordinates

Coordinates relative to the upper left corner of the screen.

scroll bar

A window control that converts mouse or keyboard input into values that a window procedure can use to shift the contents of a window's client area either horizontally or vertically. See also window procedure.

scroll box

A movable area in a scroll bar that indicates the position of the information currently displayed in the associated window. The position of the scroll box is relative to the total amount of information available for display. See also scroll bar.

scrolling

The process of shifting a data object in a window's client area in order to see parts of the object that extend beyond the border of the client area.

scrolling range

The minimum and maximum values that a scroll bar can report. See also scroll bar.

secant

A line drawn through two points on an ellipse. See also ellipse.

sector

The atomic unit of disk allocation, reading, and writing. The sector size is set when the hard drive is physically formatted, usually at the factory. 512 byte sector sizes are common.

security domain

A collection of nodes in a security database that share a common set of user and group accounts.

seek

(1) With file input and output (I/O), to change the current position in the file. (The current position is the location where the next read or write operation will take place.)

(2) With a media device (such as a hard disk), to position the medium so a certain sector can be accessed. The seek operation involves a physical movement of the device, so the time it takes can often be perceived by the user.

selection field

The portion of a combo box that displays the currently selected item. Selecting an item in the list causes that item to appear in the selection field. In simple and drop-down combo boxes, the selection field is an edit control and can be used to enter input not in the list.

semaphore object

An interprocess synchronization object that maintains a count between zero and some maximum value. The object's state is set to signaled when its count is greater than zero, and nonsignaled when its count is zero. See also synchronization object.

service

An executable object that is installed in a registry database maintained by the Service Control Manager. The executable file associated with a service can be started at boot time by a boot program or by the system, or it can be started on demand by the Service Control Manager. The two types of service are Win32 service and driver service. See also driver service, Win32 service.

service control manager

A system process that provides a unified and secure means of controlling Win32 and driver services. Each computer that is running Windows NT has a service control manager process that is started during system startup.

service name

A string that a server application responds to when a client attempts to establish a conversation with the server.

setmark

A special recorded element that contains no user data and is used to provide a segmentation scheme hierarchically superior to filemarks. Setmarks typically provide faster positioning on high-capacity tapes.

share mode

A condition that indicates whether a file is to be shared for reading, writing, both, or neither.

shared arena

The Windows® 95 shared arena (or shared address space) is the memory in the address range between 2 GB and 3 GB. It contains components that must be mapped into the address space of every process, such as the 16-bit global heap, shared system DLLs, and file views of file mapping objects. The DPMI server also allocates memory in this address range.

shared memory

Memory that two or more processes can read from and write to. If the file-mapping object that references the shared memory has a name, the memory is referred to as "named shared memory."

sharepoint

A network resource that remote applications can address specifically and use across a network--for example, a printer or a shared directory. See also container.

shearing

A transformation that alters the apparent length and orientation of vertical or horizontal lines in an object.

shell

An application that enables users to group, start, and otherwise control other applications.

short filemark

A filemark that contains a short erase gap that cannot be overwritten unless the write operation is performed from the beginning of the partition or from an earlier long filemark.

show state

The collective qualities of a window at a given time (whether active or visible; minimized; maximized; or restored).

shut down

To stop all processes, flush all file-system buffers to disk, and bring the system to a condition in which it is safe to turn off the computer.

sibling window

A child window that has the same parent window as one or more other child windows.

signaled

The state of an object used for synchronization in one of the wait functions. A signaled state can enable the wait function to return. See also nonsignaled, wait function.

signature

A 4-byte value that identifies an enhanced metafile. See also enhanced metafile.

simple combo box

A combo box in which the list box is visible at all times.

simple list

A list in a combo box that is always visible. Combo boxes with the CBS_SIMPLE style contain simple lists.

single-byte character set

A mapping of characters to their identifying numeric values, in which each value is one byte wide. The ANSI and original equipment manufacturer (OEM) character sets are single-byte character sets. See also character set, multibyte character set, Unicode.

single-selection list box

A list box in which only one item can be selected at a time.

sizing border

A type of window border that enables the user to size the window by clicking and dragging the border.

solid brush

A logical brush created from a bitmap that contains pixels of the same color. See also bitmap, logical brush, pixel.

source

A configuration registry key that specifies message-file names for replacement strings in events logged by an application, service, or group of applications. Sources are subkeys of logfile keys. See also key, logfile, subkey.

standard cursors

The default cursors that the system automatically displays when users move windows or icons, resize windows, or wait. Standard cursors include an arrow, hourglass, crosshair, and I-beam. Standard cursors are also known as system cursors. See also cursor, icon, window.

standard icons

The default icons that the system displays in system message boxes. Standard icons include, among other bitmaps, a stop sign and a circled exclamation point. See also icon.

standard resource

A resource whose format is defined and recognized by the system. Standard resources include icons, cursors, menus, dialog boxes, bitmaps, fonts, keyboard accelerator tables, message-table entries, string-table entries, and version data.

standard scroll bar

A scroll bar created as part of the nonclient area of an overlapped, pop-up, or child window. See also scroll bar.

standard VGA

A video adapter that supports a resolution of 640 by 480 pixels and 16 simultaneous colors. See also pixel.

static control

A window control that displays text and graphics that require no response from the user. Static controls are typically used in dialog boxes.

stock brush

One of seven logical brushes maintained by the system. See also logical brush.

stock pen

A cosmetic pen created and maintained by the system. There are three kinds of stock pens: black, white, and invisible. See also cosmetic pen.

streaming

The process of transferring information from a storage device, such as a hard disk or CD-ROM, to a device driver.

string atom

An atom that identifies a character string in an atom table. See also atom, atom table.

string handle

A doubleword value, assigned by the operating system, that identifies a string passed between a dynamic data exchange (DDE) client and a DDE server. See also dynamic data exchange (DDE).

stroked path

A path that is outlined by using the pen that is currently selected into an application's device context. See also device context, path, pen.

structured exception handling

A mechanism for handling hardware- and software-generated exceptions. Structured exception handling gives developers complete control over the handling of exceptions, provides support for debuggers, and is usable across all programming languages and computers.

style names

One of two attributes used to organize TrueType® fonts. Style names include extra-bold, bold, and italic. (The other attribute used to organize TrueType fonts is the family name.) See also TrueType font.

subclass procedure

An application-defined window procedure that replaces a window's original window procedure when the window is subclassed. See also subclassing, window procedure.

subclassing

A technique that allows an application to intercept and process messages sent or posted to a particular window before the window has a chance to process them. See also subclass procedure.

subdirectory

A directory within another directory. See also directory.

subkey

An entry (or node) in the registry subordinate to a given key. With the exception of four predefined keys, all keys are subkeys of other keys. See also key, registry.

sublanguage identifier

An 8-bit value identifying the variant of a language in a language identifier. See also language identifier, primary language identifier.

subtractive color mixing

A method of color mixing that uses white as the base color, from which colors may be subtracted. If you begin with white, all colors are present in equal amounts. If you subtract cyan and yellow from white, the resulting image is magenta. In a green image, subtracting cyan will result in changing the image to yellow. The subtractive primary colors are cyan, yellow, and magenta.

subtractive color technology

The color technology, used by ink-based printers, that is based on the three primary colors cyan, yellow, and magenta. Other colors (except white) are obtained by combining two or more of the primaries in varying amounts. White is defined as the absence of the primaries. Black is defined as the presence of all the primaries.

super VGA

A video adapter that supports resolutions higher than 640-by-480 pixels or more than 16 simultaneous colors (or both).

superclass procedure

An application-defined window procedure that replaces the window procedure for a window of a particular window class when the class is superclassed. See also superclassing, window procedure.

superclassing

A technique that allows an application to create a new window class that has the basic functionality of the existing class, but with enhancements provided by the application. See also superclass procedure.

syllabary

A single character that represents what we would call a syllable, using consonant/vowel combinations as their linguistically-discrete units — for example, the sound created by "ta." This term would apply to Kana (Katakana and Hiragana) and Hangul scripts. Linguists use the word "syllabary" to define a system of phonemic (linguistically-distinct) syllabic units used in a language.

synchronization object

An object whose handle can be specified in one of the wait functions to coordinate the execution of multiple threads. Synchronization objects include change notification, console input, event, mutex, process, thread, and semaphore objects. See also object, wait function.

system directory

The directory that contains system dynamic-link libraries, drivers, and font files. See also directory.

System menu

See Window menu.

system metric

A dimension of a display element, such as the border width, scroll bar arrow height, icon height, and so on. System metrics may also describe other aspects of the operating system, such as whether a mouse is installed, whether double-byte characters are supported, and so on. See also scroll bar.

system paging file

The storage file that the system uses to hold pages of memory swapped out of RAM.

system palette

An array that identifies all of the colors that can be displayed simultaneously on a device. For most displays, this array is a subset of all possible colors that can appear on the display.

system time

The "real-time" clock format. System time uses a structure containing individual members for the date and time.