A character is the basic element in a font. In GDI, each character is contained within a rectangular region known as a character cell. This rectangular region consists of a specific number of rows and columns, and possesses six points of measurement: ascent, baseline, descent, height, origin, and width. The following list describes these measurements:
| Measurement | Description | |
| Ascent | Specifies the distance in character-cell rows from the character-cell baseline to the top of the char-acter cell. | |
| Baseline | Serves as the base on which all characters stand (some lowercase letters have descenders, such as the tail of the g or y, that descend below the baseline). | |
| Descent | Specifies the distance in character-cell rows from the character-cell baseline to the bottom of the character cell. | |
| Height | Specifies the height of a character-cell row. | |
| Measurement | Description | |
| Origin | Used as a point of reference when the character is written on a device or a display surface. The origin is the upper-left corner of the character cell. | |
| Width | Specifies the width of a character-cell column. |
Figure 2.12 shows a character cell that contains an uppercase A. The baseline appears at the top of the second row. Note that the uppercase A uses the baseline as its starting point. Also note that the width and height values refer to the character-cell width and height, not the width and height of the individual character: