Glossary
absolute coordinate entry The process of specifying a point by typing in a coordinate. The coordinate is measured from the origin or 0,0 point in the drawing.
acquired point Object tracking feature used to locate a point as an intermediate location in order to locate temporary alignment paths. Acquired points show up as a small cross in the drawing. Some points are acquired by simply placing your cursor over key object definition points while other acquired points require selecting a point with your mouse.
annotate To add text, notes, and dimensions to a drawing to communicate a complete design by indicating materials, locations, distances, and other key information.
array A rectangular, circular, or linear pattern of objects.
associativity A link between drawing objects and dimension objects. Associative dimensions will update and follow the drawing objects to which they are linked.
autosave The automatic saving of your drawing by AutoCAD at regular intervals. The default save interval is 10 minutes. Autosave files have a .5V$ file extension by default and are automatically deleted when the drawing is closed normally.
AutoTracking AutoCAD feature that helps you to draw objects at specific angles or in specific relationships to other objects. When you turn on AutoTracking, temporary alignment paths help you create objects at precise positions and angles. Both orthogonal and polar tracking are available.
block attribute A dynamic text-like object that can be included in a block definition to store alphanumeric data. Attribute values can be preset, specified when the block is inserted, or updated anytime during the life of a drawing. Attribute data can be automatically extracted from a drawing and output to an AutoCAD table or an external file.
block definition A user-defined collection of drawing objects assigned a base point and a name that is stored centrally in a drawing. A block can be inserted in a drawing multiple times as a block reference. When a block definition is updated, all block references with the same name are automatically updated.
block reference An instance of a block definition inserted in a drawing that references the central block definition drawing data. All that is stored with the block reference is an insertion point, scale, and rotation angle. All other data are derived from the block definition.
B-spline An approximate spline curve also referred to as a nonuniform rational B-spline, or NURBS, curve.
building a selection set The process of specifying the objects you wish to edit. You can add and remove objects to a selection set and reuse previous selection sets.
cell The box at the intersection of a table row and column that contains the table data or a formula. A cell is typically referenced using its column letter and row number separated with a colon. For example, the cell in column A and row 1 is referenced as A:1.
chamfer To cut off a corner with a slight angle or bevel.
character set The set of numeric codes used by a computer system to represent the characters (letters, numbers, punctuation, etc.) of a particular country or place. The most common character set in use today is ASCII (American Standard Code for Information Interchange).
color-dependent plot style Plot style that is organized by the AutoCAD Color Index (ACI) number. Color-dependent plot styles are automatically assigned by the color of the AutoCAD object. All objects with the same color are assigned the same plot style settings. Color-dependent plot styles are stored in .CTB files.
command alias An abbreviated definition of a command name that enables you to enter commands more quickly at the keyboard by entering the first one or two letters of the command name. Appendix C contains a complete list of the default AutoCAD command aliases.
contour line A line on a map that joins points of equal elevation. On a single contour line, all points have the same elevation. Contour lines are typically placed at designated vertical intervals to indicate elevation changes.
coordinate entry The process of specifying point locations.
crossing window A method of selecting objects in a selection set by specifying a rectangular area. Anything that touches the crossing window area is selected.
curve fit The process of adding vertex points to a straight line segment polyline in order to create a smooth curve. Adding more points creates a smoother curve fit.
deferred point Object snap feature that allows you to “build” the object snap point using multiple point selection input by deferring the first point selected so that it can be used in conjunction with other point or object selections. For example, to find the intersection of two lines that don’t physically intersect but that would intersect if they were extended in the same direction requires that you pick both lines. The first point selection is deferred while you pick the second line. Deferred point AutoSnap markers are followed by an ellipsis (…), indicating that more information is needed.
defpoint Point created when placing dimensions that defines the measurement value of the dimension. AutoCAD measures the distance between the defpoints and uses the value as the default dimension text.
demand loading Loading only the visible part of a referenced drawing. Other parts of the drawing are loaded only when necessary. AutoCAD uses demand loading to increase system performance when xrefs are used.
dimension style A collection of dimension settings that control how dimension objects act and are displayed.
direct distance entry The process of specifying a point by dragging the AutoCAD cursor to specify direction and typing in a distance.
drawing template A drawing used as a starting point when creating a new drawing. Drawing templates can contain page layouts, borders, title blocks, layer settings, and many other settings or drawing objects you use on a regular basis. Drawing templates have a file extension of .DWT.
edit reference in-place Using the REFEDIT command to make changes to an externally referenced drawing. This allows you to make changes to one drawing from within another drawing.
fillet To round off an inside or outside corner at a specific radius.
freeze/thaw Hiding or displaying the contents of a drawing layer. Objects on a frozen layer are ignored by AutoCAD, are not shown in the drawing, and cannot be edited.
fuzz distance Distance used to determine whether polyline endpoints that are not connected can be connected by extending them, trimming them, or connecting them with a new polyline segment.
grips Editing points that appear at key locations on drawing objects. Once grips are activated, you can directly modify drawing objects by selecting their grips.
hatch boundary The edges of a hatched area. These edges can be closed objects (such as a circle or closed polyline) or a combination of objects that define a closed area.
hatch islands Closed areas within a hatch boundary. You have the option of telling AutoCAD how to deal with island areas when creating hatch objects.
hatch pattern The pattern used to fill a hatch boundary. Hatch patterns are defined in .pat files and also include solid and gradient fill patterns.
hatching The process of filling in a closed area with a pattern. Hatching can consist of solid filled areas, gradient filled areas, or areas filled with patterns of lines.
implied windowing Feature that allows you to create a window, crossing, or lasso selection automatically by picking an empty space in a drawing to define the first corner point. The opposite corner point defines a window selection if it is picked to the right of the first corner point and a crossing selection if it is picked to the left. It is also possible to drag a lasso around a selected object.
layer A collection of object properties and display settings that are applied to objects.
layout 2D page setup created in paper space that represents the paper size and what the drawing will look like when it is printed.
layout viewport The user-defined window created in a paper space layout that allows you to view drawing information that resides in model space. Layout viewports are sometimes referred to as “floating” viewports because they can be moved, copied, and resized unlike the “tiled” viewports created in model space that are static and must abut each other.
model The geometry (lines, circles, etc.) created in a drawing that defines the object or objects drawn. The graphical representation of the real-world object or part.
named plot style Plot style that is organized by a user-defined name. Named plot styles can be assigned to AutoCAD layers or hard-coded to individual drawing objects. Named plot styles are stored in .STB files.
nested xref An xref within an xref. This occurs when the drawing you are referencing contains a reference to another drawing. For example, you reference drawing A, and drawing A contains a reference to drawing B; drawing B is the nested xref.
objects Graphical drawing elements, such as lines, arcs, circles, polylines, and text.
object snaps/osnaps Geometric points on objects such as the endpoints or midpoint of a line or the center of an arc or a circle. Object snaps can be construction points on objects or calculated points such as a point of tangency, a perpendicular point, or the projected intersection of two drawing objects.
offset To create a parallel copy of an object.
orthographic 90° increments. When the Ortho mode is turned on, AutoCAD locks the cursor movement to 0°, 90°, 180°, and 270° angles.
orthographic projection The two-dimensional graphic representation of an object formed by the perpendicular intersections of lines drawn from points on the object to a plane of projection. Orthographic projection is a drafting technique commonly used to create multiple view drawings by creating one view, then projecting perpendicular lines from the complete view to create the other views. This approach limits the number of times you need to measure in your drawing, reducing errors and increasing productivity.
page setup A collection of plot settings that are applied to a drawing layout. Page setups can be used and shared among multiple drawings.
pan The process of moving your drawing from side to side in the display window so the location of the view changes without affecting the zoom scale.
parametric Automated creation of a drawing based on a given set of dimensions referred to as parameters. These input parameters are applied against algorithms that create points, distances, and angles for the creation of drawing geometry. A simple example of creating a drawing parametrically is entering a width (X) and a height (Y) to create a rectangle.
parametric design Design process that utilizes both variable and constrained dimensions that automatically update the drawing objects they are assigned to so that many different variations of a base design can be accurately represented.
parsec A unit of astronomical length based on the distance from Earth at which stellar parallax is one second of arc and equal to 3.258 light-years, 3.086 × 1013 kilometers, or 1.918 × 1013 miles.
.PC3 file Plotter configuration file used to store and manage printer/plotter settings. .PC3 files control plot device settings such as port connections and output settings, media, graphics, physical pen configuration, custom properties, initialization strings, calibration, and user-defined paper sizes.
pickbox Square box that replaces the cursor crosshairs whenever AutoCAD prompts you to Select objects:. It is used to pick objects in a drawing to create a selection set.
plot style A collection of property settings defined in a plot style table that is applied when the drawing is plotted to control the appearance of the drawing objects on the printed drawing. Plot styles can be used to control line thickness, grayscale, screening, and other plot features.
plotting The process of printing a drawing in AutoCAD. Plotting includes outputting your drawing to printers and plotters as well as various electronic file formats.
point A one-dimensional object that is defined as a single coordinate in space. Points have no length or width, only a coordinate location. Points are referenced with the Node object snap.
polar tracking A process in which AutoCAD will lock the cursor movement to predefined angles. When the cursor gets close to one of these predefined angles, AutoCAD will lock onto that angle and display the angle measurement at the cursor.
printable area The actual physical area that can be printed for the currently specified plotting device and paper size. Most printers cannot print to the very edge of the paper because of mechanical limitations.
properties The settings that control how and where a drawing object is shown in the drawing. Some properties are common to all objects (layer, color, linetype, and lineweight) or specific to a particular type of drawing object (the radius of a circle or the endpoint of a line).
revision cloud Continuous line made from arcs to resemble a cloud that is used to highlight markups and changes. Sometimes marked with a delta triangle indicating the revision number or letter.
right-hand rule Easy-to-understand reference that can be used to determine the positive and negative direction of the X-, Y-, and Z-axes. To use the right-hand rule, you clench your right hand into a fist with your palm facing toward you and extend your thumb to the right, point your pointer finger straight up, and point your middle finger toward you. If your palm is the origin at 0,0,0, then your thumb represents positive X, your pointer finger represents positive Y, and your middle finger represents positive Z.
rubber band A live preview of a drawing object as it is being drawn. The rubber-band preview allows you to see objects as they are being created.
scale factor Multiplier that determines the size of annotation features such as text height, dimension features, and linetype appearance when a drawing is plotted or printed. The scale factor is typically the reciprocal of the plot scale or view scale.
selection set One or more selected objects that are treated as one unit by an AutoCAD command. Objects in a selection set are typically highlighted (dashed).
sheet set An organized and named collection of sheets created from multiple AutoCAD drawing files.
sheet size The size of the paper on which a drawing is printed or plotted.
standard colors Colors 1–9 of the AutoCAD Color Index.
system variable A named setting maintained by AutoCAD that controls an aspect of a drawing or the drawing environment. Most system variables can be changed by entering the variable name at the command line, although some variables are read-only and cannot be changed.
transparent command A command that can be used without interrupting the currently active command. Most display commands can be used transparently so that you can pan and zoom in a drawing while simultaneously using the drawing and editing commands. Transparent commands are run by entering an apostrophe (‘) before the command name.
typeface The style or design of a font. Other unique properties include size, boldness (line thickness), and obliqueness (an angle applied to the characters, not to be confused with an italic font).
underlay A CAD file that is not directly modifiable by AutoCAD but is still displayed within a drawing and updated when the source data are changed. AutoCAD currently supports the display of DWF and DGN files as underlays.
unit block A block or symbol drawn within a 1 × 1 unit square that is inserted in the drawing with different x and y scales to achieve different final sizes.
user coordinate system (UCS) A user-defined variation of the world coordinate system. Variations in the coordinate system range from moving the default drawing origin (0,0,0) to another location to changing orientations for the X-, Y-, and Z-axes. It is possible to rotate the WCS on any axis to create a UCS with a different two-dimensional XY plane—a technique commonly used to create multiview 3D drawings.
user interface The commands and mechanisms the user interacts with to control a program’s operation and input data.
variable User-defined unit of storage that may assume any given value or set of values. Variable values are dynamic and can change at any time. Often variables are assigned data types so that they can store only specific types and amounts of data.
viewport A window in the paper space environment that shows the view of the model space environment.
working set The group of objects selected for in-place editing using the REFEDIT command. Objects can be added to and removed from the working set using the Refedit toolbar during the in-place editing process.
workspace A named configuration of menus and palettes that are grouped and organized so that you can work in a custom, task-oriented drawing environment.
world coordinate system (WCS) The default coordinate system in AutoCAD upon which all objects and user coordinate systems are based.
xref A drawing that is referenced by another drawing. The drawing references are updated when the source drawing is modified.