The digital image is the Two-dimensional representation of an image using bits, a minimum unit of information made up of binary digits (1 and 0), which is used at the behest of computing and any digital type device.
According to the resolution presented in the image, static or dynamic, you can talk about raster chart (or bitmap; represents a rectangular grid of pixels or color point, which can be displayed on a monitor, on paper or in any other representation device that is used) or vector graphic (Image product of independent geometric objects; the main difference that it presents with respect to the previous one is the possibility of enlarging the size of the image without losing its scale as happens in the case of raster graphics), respectively.
Meanwhile, the digital image can be obtained from digital analog conversion devices, such is the case of the scanners and digital cameras , or failing that through relevant computer programs such as drawing with the mouse or through a 2D rendering program.
It should be noted that it is absolutely modification of digital images possible By means of filters you can add or delete certain elements that you do not have or, on the contrary, remove those that you do not want, likewise, you can modify the size of an image and, if necessary, even save it on a storage device Such is the case with a CD or the computer's own hard drive.
Regarding their conformation, most digital formats respect the same structure: header with attributes: image size and type of encoding, among others; data from the image itself. Both the attributes and the data of the image will be different in each format.
On the other hand, many of the formats of digital cameras and video cameras that are used today, have added an area called metadata (data that describes other data).