> For the complete documentation index, see [llms.txt](https://docs.sevenpens.com/drawtab/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.sevenpens.com/drawtab/core/active-area.md).
# Active area
## Introduction
The **active area** of a drawing tablet is the rectangular region of the tablet's surface that detects the EMR pen. Some manufacturers, such as Wacom and XP-Pen, use the term **active area**, while others, such as Huion, use the term **working area**.
When we talk about the "size" of the drawing tablet, we are referring to the active area.
## Active area of pen tablets
The active area is usually marked in some way on the surface. Sometimes it is marked at its four corners. Some tablets show a grid of dots.
 
## Active area of pen displays
The active area of a pen display is easy to identify because it is exactly the same area as the display panel.
## Size
Usually, when we discuss the size of an active area, we mean its diagonal length. Drawing tablets vary quite a bit in active area size. More here: [Active area size](/drawtab/core/active-area/active-area-size.md).
## Aspect ratio
The relationship between the width and height of the active area is its aspect ratio. More here: [Active area aspect ratio](/drawtab/core/active-area/active-area-aspect-ratio.md).