pixels, 

a minute area of illumination on a display screen, one of many from which an image is composed.

image resolution,

the detail an image holds.

 megabyte,

A measure of a computer's disk storage capacity or a computer file's size

 megapixel,

a unit of graphic resolution equivalent to one million or (strictly) 1,048,576 (220) pixels.

jpeg, 

a format for compressing image files.

psd,

the default format that Photoshop uses for saving data.

 white balance

the color balance on a digital camera.

, histogram, 

a diagram consisting of rectangles whose area is proportional to the frequency of a variable and whose width is equal to the class interval.

aperture,

an opening, hole, or gap.

 shutter speed,

the time for which a shutter is open at a given setting.

 depth of field,

the distance between the nearest and the furthest objects that give an image judged to be in focus in a camera.

 bitmap,

a representation in which each item corresponds to one or more bits of information, especially the information used to control the display of a computer screen.

 exposure,

how much light their is in the picture

 watermarking,

The artist's name or signature on the picture to show that it's theirs

 optical zoom,

zoom in (or out) on the subject in the LCD or viewfinder.

 digital zoom,

 One type of digital zoom simply "crops" the edges of the image.

 light meter,

an instrument for measuring the intensity of light, used chiefly to show the correct exposure when taking a photograph.

 image stabilization

techniques used to reduce blurring associated with the motion of a camera or other imaging device during exposure.

, noise,

variation of brightness or color information in images, and is usually an aspect of electronic noise.

 lag time,

is the delay between triggering the shutter and when the photograph is actually recorded

 hot shoe,

a bracket on a camera body that provides support and electrical contact for an electronic flash attachment

 fisheye, 

 lens Expand.

macro

 is classically a lens capable of reproduction ratios of at least 1:1

, telephoto,

 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, 

refers to a lens whose focal length is substantially smaller than the focal length of a normal lens for a given film plane.

DSLR.

 is a digital camera combining the optics and the mechanisms of a single-lens reflex camera with a digital imaging sensor, as opposed to photographic film