True or False: An image is always a raster, and a raster is always an image.

The assertion that "an image is always a raster, and a raster is always an image" is false because while images are typically represented in raster format—comprising a grid of pixels where each pixel represents color or intensity—raster data encompasses more than just images. Raster data can include various forms of data representing continuous phenomena, such as elevation surfaces, temperature distributions, and satellite data, which do not necessarily constitute an image in the traditional sense.

Furthermore, a raster can represent a range of data types beyond visual imagery, including categorical data, which may not be visually interpretable as an image. Hence, while every image is, by definition, a raster, not every raster qualifies as an image, making the statement provided incorrect. Thus, the understanding that raster data encapsulates a broader category than just imagery is crucial in distinguishing the differences between these data types.