PHOTOGRAPHY DEFINITIONS

Pixel:a minute area of illumination on a display screen, one of many from which an image is composed.
image resolution:Resolution refers to the number of pixels in an image. Resolution is sometimes identified by the width and height of the image as well as the total number of pixels in the image.
Megabyte:a unit of information equal to 220 bytes or, loosely, one million bytes.
Megapixel: a unit of graphic resolution equivalent to one million or (strictly) 1,048,576 (220) pixels.
Gigabyte:a unit of information equal to one billion (109) or, strictly, 230 bytes.
Jpeg: a format for compressing image files.
Raw: A camera raw image file contains minimally processed data from the image sensor of either a digital camera, a motion picture film scanner, or other image scanner.
Tiff: is a computer file format for storing raster graphics images, popular among graphic artists, the publishing industry, and photographers
Png: Portable Network Graphics
white balance: The process of removing unrealistic color casts, so that objects which appear white in person are rendered white in your photo
Histogram: An image histogram is a type of histogram that acts as a graphical representation of the tonal distribution in a digital image.
Aperture: In optics, an aperture is a hole or an opening through which light travels.
shutter speed: The amount of light that reaches the film or image sensor is proportional to the exposure time
depth of field: depth of field is the distance between the nearest and the farthest objects that are in acceptably sharp focus in an image. 
aperture priority: is a setting on some cameras that allows the user to set a specific aperture value while the camera selects a shutter speed to match it that will result in proper exposure based on the lighting
shutter priority: a setting on some cameras that allows the user to choose a specific shutter speed while the camera adjusts the aperture to ensure correct exposure.
Bitmap: images are stored as a series of tiny dots called pixels.
Exposure: exposure is the amount of light per unit area reaching a photographic film or electronic image sensor, as determined by shutter speed, lens aperture and scene luminance
Watermarking: ext placed over a photograph usually as a method of identifying the image's creator.
optical zoom: This will enable you to get a closer view of the subject before taking your picture.
digital zoom: Digital zoom is a method of decreasing the apparent angle of view of a digital photographic or video image.
Bracketing: the general technique of taking several shots of the same subject using different camera settings
light meter: A light meter is a device used to measure the amount of light. In photography, a light meter is often used to determine the proper exposure for a photograph
image stabilization: techniques that reduce blurring associated with the motion of a camera or other imaging device during exposure
Noise: Image noise is random variation of brightness or color information in images, and is usually an aspect of electronic noise. 
lag time: Shutter lag time simply means the time it takes from when you press the shutter button to when the camera actually records the picture
hot shoe: is a metal bracket on top of your camera with electrical contacts where an external device can be connected.
Fisheye: A fisheye lens is an ultra wide-angle lens that produces strong visual distortion 
Macro: Macro photography, is extreme close-up photography, usually of very small subjects
Telephoto: In photography and cinematography, a telephoto lens is a specific type of a long-focus lens in
which the physical length of the lens is shorter than the focal length.
wide angle: a lens whose focal length is substantially smaller than the focal length of a normal lens for a given film plane.
DSLR: a digital camera that combines the optics and the mechanisms of a single-lens reflex camera with a digital imaging sensor
dynamic range: the difference between the darkest and lightest tones in an image,
generally pure black and pure white
exposure compensation: it is used to alter exposure from the value selected by the camera, making photographs brighter or darker