An entity is the basic unit of a LAYOUT drawing
A LAYOUT drawing is made up of "entities." An entity consists of a starting point, an ending point, and a line or arc between these two points. The drawing tools always create entities made up of lines and arcs. For example, the Box command creates four line entities connected at the corners, while the Circle command creates two arcs.
In the following figure, each entity has been assigned a different color, so you can see where they are. Note that the "box" is really four line entities that exactly overlap end points. Similarly, a "circle" is really two arc entities. Everything in LAYOUT is composed of either a line or an arc.
A "box" is four line entities; a circle is two arc entities
The concept of entities becomes important when changing a drawing in LAYOUT . To move a box, for example, select all four entities that make it up.
An entity is always marked at each end with a point. The points of all entities in the drawing can be displayed by using the Show Dots command.