Glossary
Plain-English definitions for the AutoCAD and Plant3D terms our docs use most — useful even if you use AutoCAD every day but have never needed the precise difference between, say, a block reference and a block definition.
Asset (Plant3D)
A piece of plant equipment — a valve, pipe run, fitting or instrument — modeled as a Plant3D-specific object, not a plain block.
Asset class
The Plant3D category an asset belongs to — e.g. A_BallValve, A_Pipe — comparable to a block definition for ordinary blocks.
ATTSYNC
AutoCAD's built-in command for syncing block references to a redefined block's current attribute set.
Block attribute
A named, editable text field attached to a block — like a title block's "Drawing No." or "Revision" field.
Block definition
The reusable master symbol stored once in a drawing — the template every instance of it points back to.
Block reference
One placed instance of a block definition — what most people just call "a block" in a drawing.
CTB (Color-dependent plot style table)
A plot style file that maps each of AutoCAD's 255 colors to a print appearance (line weight, screening, color override).
DBText (single-line text)
AutoCAD's older, single-line text object — one line, one uniform style, no in-line formatting.
DWG
AutoCAD's native binary file format for a single drawing.
DXF
A text- or binary-based drawing exchange format that mirrors DWG's structure.
Dynamic block
A block definition with built-in parameters that let a single reference change shape, size or visibility state without being redefined.
Handle
A unique, permanent identifier AutoCAD assigns to every object in a drawing.
Layer
A named category used to group objects and control their color, linetype and visibility together.
Layout
A named paper space tab representing one printable sheet.
Model space
The full-scale drawing environment where the actual design geometry lives.
MText
Multiline, paragraph-style text with per-run formatting (bold, color, fonts mixed within one object).
Paper space
The layout environment used to compose a printable sheet from model space geometry.
Plant3D Project Database (ProcessPower.dcf)
The project-wide file (ProcessPower.dcf) where Plant3D stores UDA values and other data not kept on the drawing itself.
Tag (Plant3D)
The unique identifying label a Plant3D asset carries, e.g. a valve number — analogous to a name plate.
UDA (User-Defined Attribute)
A custom property Plant3D lets a project define for an asset class, beyond the built-in fields.
Viewport
A window on a paper space layout that shows a scaled view into model space.
Xref (External reference)
A drawing linked into another drawing by reference, rather than copied into it.