What characterizes a bitmap graphic?

A bitmap graphic is defined by its structure of storing images as a grid of individual pixels, with each pixel represented by a binary value that indicates its color. This representation allows for detailed images where each pixel contributes to the overall picture. The binary data format enables the accurate reproduction of colors and details, which is the fundamental characteristic of bitmap graphics.

The other options provide different characteristics associated with other types of graphics. For instance, mathematical formulas are a hallmark of vector graphics, which represent images using lines, curves, and shapes defined by equations rather than pixels. A predefined palette is often used in indexed color images but does not define all bitmap graphics, as many can utilize a wide range of colors. Finally, containing only text characters is a typical feature of text files or fonts, not bitmap graphics, which are primarily concerned with visual image representation rather than text alone.