When we say something is to scale it means it is a standardized measurement using actual dimensions that are represented by a smaller unit of measurement. These smaller increments of measurement allow us to represent a larger object in a proportionate way but at a reduced size, not full size. So one could say it has been scaled down.
Designers use scaled drawings to create standarized illustrations.
This may be because drawing the item at full size would be unmanageable, or would not easily fit on a single sheet of paper (such as a building), or alternatively because items need to be drawn larger than full size to adequately represent all the detail that needs to be communicated (such as a complex connection).
The scale of drawings is described as a ratio using the notation (1:50, 1:250). A distance at full size, the distance at the scale used that would be the same length.